As far as I recall there is no possibility to apply for individual habitation certificates on a complex of individual units. The application is made for the entire project for all properties. Therefore, it could be a long way off. 50 x 2000 TL will be very difficult to obtain and the feeling from some will be that they should not pay and will not pay. Getting 50 people to sign and return something is near on impossible, so asking 50 people for 2000 TL (that they have already paid in the asking price) is not going to be child's play.
To be honest, 100,000 TL (£ 34,000) sounds like a lot but it is nothing to a developer (a single stage payment on one villa). You can read into that what you like.