Visas are required for entry into Turkey by nationals of most countries. However, many of the visas can be purchased for 15-20.-USD at Turkey’s airports or border gates and citizens of many countries can enter Turkey without any visas for 90, 60 or 30 days. 77 countries do not require a visa and 122 countries can purchase a visa at the border.
Ministry of foreign affairs also supply an e-visa service on their web site which makes to get visa much more easier. Applicants just need to log on to www.evisa.gov.tr , provide the requested information, (after the application is approved) make online payment and download their e-Visa. The whole process takes no more than 10 minutes.
You may find the latest information about visa procedure in http://www.mfa.gov.tr/visa-information-for-foreigners.en.mfa
An official letter of invitation will be sent to you upon request.The invitation letter may be used by visitors to raise travel funds or to obtain a visa, but is not a commitment on the part of the organisers to provide any financial support.
Turkey has a relatively free market for trade in goods and services and follows basic World Trade Organization (WTO) rules to regulate imports and tariff structures and has adopted the European Union (EU)’s common customs tariff for imports from third countries.
Visitors may bring an unlimited amount of Turkish or foreign currency with them into Turkey, but they may take out of the country only 5.000.-USD or other currencies in cash equal to this amount. There are no restrictions on the transfer of Turkish or foreign money to other countries through banks.