Gains in prices of residential real estate in Bulgaria's 28 biggest cities and towns averaged 28,9 % in 2007 over the previous year, data of the country's National Statistics Institute (NSI) showed on Wednesday. The average price paid for residential properties last year in the areas covered by the NSI survey was BGN 1091,24/m2. Capital Sofia, which boasts the highest salaries in the country, remains the nation's most expensive housing market with an average price of BGN 1813,17/m2, a 35,1% increase over the previous year. The port city of Varna came in second, commanding an average price of BGN 1762,63/m2, up by 33,9% over last year. Third ranked the other major port of Burgas with average residential property prices at BGN 1442,08/m2, posting a 17,5% surge over the previous year. The residential real estate in Sofia district bottomed the ranking with prices as low as BGN 488,14/m2, marking an increase by 18,6% compared to the previous year.