Buying an Ultralight. Whats the CHEAPEST way to get me airborne?

I live in Upstate NY and I'm interested in purchasing a powered ultralight of any type... maybe even a balloon, something to just get me airborne. My one hang-up is cost so I think I want to buy a used ultralight to save money. My question is what is the cheapest way to accomplish this? I would be willing to construct or emble parts if necessary.