Clearance sales are a good idea. But don't go too cheap without a clearance, or you'll get what amounts to a plastic garbage bag that, as others have mentioned, will keep you soaked in sweat.
A good cycling jacket has pit zips and a back vent to help you regulate heat when in gets cool (and you have a chance to delay soaking for a hour or two). It'll have a liner, so you don't experience that rubber next to wet skin feel. It may have a two way zipper, again to help regulate heat inside the jacket. Unfortunately, those features don't come in wally-world cheap jackets.