expensive

1a. I won’t hire Raman to renovate our house because he’s expensive. He charges a lot.
1b. I won’t hire Raman to renovate our house because his charges are expensive.
Are these sentences OK?
Thanks.

1a is fine, though 1b sounds a little odd. I would say “because his services are expensive” or “because his prices are high” or “because he charges a lot”.

Luschen,
Thanks.
'He’s expensive." Is it OK?
When I think in the way of our language, it looks some what odd.
Is it allowed in English?
Please comment. Thanks.

Luschen has already commented and explained that the sentence is okay.

The term would be accepted as meaning:
he is expensive to hire
or
his rates are expensive.

I agree it might sound a little odd to non-native speakers, but as Beeesneees says, it sounds quite natural in this context.