i found some god old silver coins and turkish republic coins in the antique shops of Beyoglu in Taksim Istanbul. mostly a good selection of 1-2 hundred year old coins from the middle east and eastern europe. stay away from any roman/greek/or other ancient coins. they are almost all fake. also it is illegal to sell, buy, or take them out of the country. even if you are caught leaving with fake roman coins the customs people may not be able to tell and you could be detained.