Joannesalfa : spending money in antipiracy measure isn't very wise, but you need to have a "minimum of antipiracy" baked in, to aovid losing all customers.
The thing is that people always go for the route that is less costly. If you use a simple technique that needs an hour of online search to crack, "regular" customer are going to buy your game instead of losing one hour, and typical crackers are going to crack it anyway.
Think about the 80/20 rule : 80% of the money comes from 20% of the customers. So make it hard for those 20% of customer to have a cracked version. And only for them, no more, because what is invested on top of those 20% is lost money.
that means very simple trick like : CRC check of the binary file size, serial key (meaning having a server to check that, or a keycheck injected inside the binary), or demo/complete versions of the game. Nothing fancy, everything already invented, but that's sufficient to dether piracy from the "mom's and dad's" (what a clich� ! ;)) playing your game (and after all, they have the money anyway to pay, not the youngsters).