If you would sell your apartment before kepping it for 5 years you are going to be responsible with Capital Gains Tax from your profit. According to the government your profit will be the difference between the value of apartment on title deed and your apartment's sales price.

According to your property, if your apartments value on your title deed (TAPU) is 100,000.00.-YTL and if you would like to sell the apartment for 140,000.00.-YTL before keeping it for 5 years; this means you are going to be responsible with Capital Gains Tax from 40,000.00-YTL which means from your profit.

Basically here is the rate schedule for 2008:

The Tax Base Tax
0- 7,800 YTL 15%
7,801-19,800 YTL 20%
19,801-44,700 YTL 27%
44,701- and over 35%