It depends, if you use non-creative commons/non licensed samples then no, you'll be in big doo-doo if somebody finds out. MAKE SURE YOUR DRUM SAMPLES AND SOUNDFONTS ARE ROYALTY FREE! Musicradar has a great library of free samples and loops. Also your melody has to be original too, but that's a given...

Really, it doesn't matter if it's 25 for 125. Unless you're a grandmaster pianist, your melodies will be limited
to around two octaves anyway. Plus, you'll probably have to edit the notes in the piano roll too.