How to buy an iPhone on the Internet and do not become a victim of fraud?
Always choose a trusted sellers with a good reputation. Ask him to send IMEI and Serial numbers.
Check Serial Number at www.sndeep.info and compare basic tech spec. (model, color, memory size, etc.).
Then, check the IMEI at www.sndeep.info/en/iphone_info page. Choose Basic + Find my iPhone options.
The results of checking will be like: