Where can I buy some coins with the cheapest price? Too many exchanger & trading sites out there, you don't know which is the best one.
You just need to look at coinmarketcap and you will see each of their price's difference. But I would say that finding that cheapest is useless because they only differ in a thousands of sats.
There are so many important things which you need to keep in your mind before making any such kind of decision like that of buying of any of the crypto coin. You first need to look at your financial status and that after that, you need to study well about all the possible crypto coins and then you need to make the best possible choice based on your skills as well as the money which you have for investing.