Fee/Rake question

[KikoSanchez]

Hi, I am new to sports betting. I was just curious I noticed when I make wagers, sometimes you can bet, for instance $12 to win $10, but sometimes it's 10 to win 10 or even 10 to win 12. It seems a lot of the picks I see lean toward wagers that require you to wager a bit more than you are hoping to win (bet $12 to win $10). Is this pretty uniform across all wager sites, or are there some with lower 'rakes' or whatever it may be called. For ex: one place has $12 to win $10 and another has $11 to win $10, but with the same line and everything.