Hi,
Here’s my 2 cents worth. I’ve pointed out what I would do differently, so that you can have a look. I hope it will help. Good luck with the studying.
Based on what the books say they are looking for:
Clearly identifiable structure. Some of the ideas could be supported more strongly. Closing needs a bit of work to tie it in with the rest of the text.
Vocab’s fine with a couple of hick-ups (thank goodness they don’t expect Pulitzer prize worthy, although sometimes I wonder …) You can easily avoid a couple of grammar issues if you have a look at them. (and are able to remember what you found with everything else that needs juggling while the clock is ticking)
Points to have a look at:
- Instead of repeating the “Some people” from the question, try to use a similar phrase: “There are those who believe” or just leave out “people” = “Some believe that…” to make yours a bit different.
- Check after you’ve finished writing that you have used I only with a capital letter. In e-mails it’s now common to use small letters, but they’ll count that as a spelling mistake. Either get used to always use capital I or check after you’re done, easy fix.
“I, myself” is a construction that is commonly used, but considered bad usage by some. Don’t risk getting dinged for it. Your construction “I strongly suggest…” is not usually used in this meaning. We use it in conversations to make a point that we want someone to do something “I strongly suggest that you buy a ticket” (Instead of “I don’t want any trouble. Go buy a ticket!”) We also use suggest as a synonym for “show, indicate, imply …” but then with non-people nouns e.g. The smell suggested that there was a fire. / The note suggested that students were not paying their association dues on time.
“I think that” , “I feel that” are better synonyms
"I am of the opinion that " or “I hold the opinion that” can sound a bit stilted. Rewrite the sentence to start “In my opinion higher education …” (without “that”).
Watch where your “only” goes, do you mean “only be available” or are the students “only good” (this would imply they could be better as in:. “They are only good, not excellent students.”} (I noticed you either used a bad topic copy or copied it out with that error. “Some people believe that a college or university education should be available to all students. Others believe that higher education should be available only to good students.” was the original. Putting “only” behind the available invites trouble, typical TOEFL trap. Sometimes it helps if you replace “only” with “exclusively” and see if it sounds right.
You don’t need hyphens with “not easy to accomplish,” I’d then put a comma.
It require >> missing something?? Where’s the snake 
“it also requires” would be better in my book than “and also” which is more a filling used in speaking.
a wide range of knowledge, in-depth knowledge, detailed knowledge…
Why would it hurt people’s feelings that a college education is expensive …? The “it” reference is ambiguous here, because the “but” phrase is not developed further, so one tends to look for the opposing term in the first part of the sentence. Maybe something like "This view may hurt people’s feelings; but since a college education is expensive …it is a position based in reason.
I always expect a “secondly” if s.o. starts their first idea of with “firstly”. One sort of looks up and down the essay and wonders “and where’s the second idea?”
How about “One issue to consider in this discussion is that higher …” since you continue with “The most important point …” maybe “A basic point to look at is that …”
“mediocre” - at least in usage in the southern US - gives a worse idea than the dictionary would have you believe. It’s used more as a synonym for “really bad” than for “average”.
“weak students” or “weaker students”, “students with a low GPA”, “students with a poor performance record” might be more like it
The TOEFL people still seem to insist on “he or she” instead of “they” as pronoun for individuals of undefined sex. A student who …proved that he or she worked …
Look at the bright side, 2 words more for the word-count.
…require(…) You do know that in positive statements in present simple (the “always and repeated” tense) you need to add an -s to the verb for an individual person, animal, thing, concept or activity you are talking about (3rd person; he, she, it), don’t you? “Higher education” = one concept = pronoun would be “it”.
Your comparison is missing the second leg Higher education requires them to put more effort into studying than high school does.
… continue studying.
There are 3 English terms for trying to find stuff: seek, search, look for. I find the following explanation useful to explain most uses:
look for - you know it is somewhere, you just don’t know where
seek - you don’t know if it exists, but if it does you want to find it
search - look for something in a defined area
Examples: I’m looking for information on “higher education”.
I’m seeking someone to help me sort out my schedule.
The police searched the house for stolen property. I searched the web for information.
“researching information” is what you wanted, I think
I think you need to use “unlike” instead of “not like” (sorry don’t know a rule for that). Your comparison has apples and pears in it if you say “unlike at” … then you have to continue with “at”… like “at college …there’s the basic drive to want …”
No brackets needed around his or her.
“Being successful” or better “Success depends mostly on hard work” (or “you working hard”. school without further info would be mistaken to mean the name of the school rather than “the highest level of school education you achieved”.
Recommended linking words for the closing would be:
Given these facts
Hence (sounds old fashioned)
In conclusion
So
Therefore
Thus (sounds old fashioned)
To conclude
Finally is used more for the last idea to support your thesis.
“The above reasons” or “the reasons stated above” would be better than starting the paragraph with a reflexive pronoun.
send … to/into, send for = ask for s.th. to be delivered to you/ s.b. to come. www.dictionary.cambridge.org has a “Phrasal verb dictionary” Some of the British ones are different from American, but that’s o.k.
…But I would not tell other students… There are some snobs that still insist you should never start a sentence with “but” used to contrast ideas. I think it’s better than having these long sentences. “This doesn’t mean I would tell…” might get you out of the jam.
Not just students, but rather everyone…