If i did not guess it wrong your contractor should be in carpentry trade. His price in all the carpentry works is much more higher. The other works like tiling, electrical, false ceiling is consider low. It is almost the price of contractor to contractor of different trade. Customer or home owner should never get such price usually. He just earn little bit for introducing other contractor to do your renovation. The only thing is you need to pay extra care on the works. Because the profit margin is very thin. There is no room for this type of contractor (hungry for deal) to make mistake and to do extra services for you when you sign the contract. So just to be careful you does not end up mouth fighting if any modification is needed during your project. Usually if i go direct to contractor, look for those with reasonable price/profit. So that the contractor give you good quality of works and more accommadating. Hope this help.