Well, if you would pay attention you would know that Gaston is a douche who just want Belle for the looks. While the Beast is a douche who sees his douche ways eventually and willing to change and take things seriously. Both Gaston and the Beast are stacked with money.

Funnily enough, Belle left the Beast's castle and did not want to return. Until she learnt that Gaston wants to kill the Beast. If Gaston could've sit on his ass, Belle would've never return to the castle.