@just_carl There aren't many coin stores still operating in Istanbul. There are virtual marketplaces (called a
mezat in Turkey that usually serious collectors buy from. They are quite similar to
ebay, yet owned and operated by individual numismatic companies.
There is a store in
Besiktas in Istanbul (actually a shop in front of the mint itself in
Be#351;ikta#351; that sells official mint products, such as NCLT, silver 1 ounce coins and commemoratives, yet after the silver boom in 2011-12, the price of 1 ounce cins has risen sharply, and never has fallen back. Many Tukish collectors stopped collecting those, back when the prices weren't lowered and arranged en par with the silver prices.
There still are a few shops here and there, usually in touristic downtown areas, but prices seem to vary a lot, and just like in Germany, chance of owners speaking English is quite low. I have heard that there are several numismatics shops in the
covered bazaar in Istanbul, but actually I have never been to the covered bazaar myself in the last 10 years.
Bullion gold is very easy to obtain from jewellery shops scattered almst anywhere in the city, there is always more than one in every high street across every single town in Turkey. Buying bullion gold can be a good idea beacuse the premium is usually just a few dollars per gram (a
full gram) when buying Turkish sovereigns (
cumhuriyet altini) which comes in several types (a quarter, 1,74gr, a half, 3,5gr, a full 7gr, a 2 1/2 17,5gr, and a fiver 35gr). They're 22ct. gold and seen as an investment in here among the locals.