[Legit] Noob question here

so i recently got hired by a big box store and ive been lurking here. found out my employer offers employees 15% off market value when purchasing stock.

would it be wise/possible to invest 3/4 of my paycheck in their stock and immediately sell it off for a 15% ROI per share?

is that a good amount to make back per share?

gotta get my canoe before i can get my yachts haha