How much personal information does the exchange require? Do you need to upload a picture of your ID?
How much can you buy? If you plan on buying a large amount, does the exchange support this much in exchange?
There are also sometimes crypto and fiat withdrawal limits on exchanges that limit how much you can withdraw at once. This can be annoying since if you deal with large amounts you will have to withdraw small amounts over a few days.
OTC markets are available for buying large amounts of Bitcoin, but these markets are yet to appear for other coins for now.
How much does the exchange charge for converting your money? And how does this fee compare to other similar exchanges?
The average fee for credit card buys are about 4%. Bank transfer buying fees are usually 1-1.5%. Compare the rates of any exchange to other similar exchanges.
Cash fees are usually 1%, although there is often a 5-10% premium. This is especially true at ATMs, where there is always a premium.
How fast will your coins be delivered? Note that most problems with speed are due to the legacy banking system and not with cryptocurrency.
Credit card buys are often instant. Bank transfer buys can take days to clear. Cash buys are instant but you have to physically move and can’t do it online.
How long has the exchange been around? Is it regulated? Many exchanges have been scams in the past, so research any exchange before you deposit money with them. buybitcoinworldwide.com