The REAL question is: "What should you do now?"

Do you still want to keep the bike?

Returning the bike is an obvious option but it doesn't accomplish your objective of obtaining a bike for the price of this one. I assume you'd be happy at that price if everything was right or you wouldn't have made the deal in the first place.

If you decide to keep the bike you still have options:
1. Make a list of everything you perceive is wrong and ask the seller to make it right. That would put you back to where you originally planned to be. Probably the most logical choice.
2. Fix it yourself. It does builds a little resentment but you will both learn about dealing with other people and learn about bike mechanics in the process. Honestly, that's probably what I would do because it keeps me from having to deal with those jabronies anymore.