that doesn't make any sense... if you're having trouble coming up with money for a wideband, then getting a standalone or a premade ecu from calum or nistune would definitely be out of your budget even if u do sell the neo. from my understanding of what i've been reading, piggybacks are the way to go for non-race use.
for budget purposes, stick with your neo and get a wideband. either way you'll need a wideband with whatever management system you get or you won't be able to tell how rich or lean your mixture is. just wait around for a used one to pop up. that's your best bet without spending a lot.