where do I buy Bitcoin the cheapest way?

so I have bought bitcoin a bunch of times but haven't figured out where do I buy them the cheapest way? sometimes they say no fee but I noticed when they reach my wallet it's not the same amount that a payed so I guess they just give you a bad exchange ???? rate? so tell me once and for all where do I buy? and I'm not interested in P2P I know there you can get even under the cost of bitcoin sometimes but I don't like it because it takes too long. I like a site where I can just enter the amount and pay with card or PayPal and be done with it. tyvm