How to buy Prius with bad engine?

I have a 2010 Prius and recently put in a rebuilt engine. Unfortunately, it looks like my brake booster is bad (& out of warranty). Don't want to pour that kind of money into a booster in a vehicle with lots of miles when something else might go wrong (hybrid battery, AC compressor, etc.). I was thinking about purchasing a Prius cheap with a bad engine (& ideally that's low mileage or has already had the booster replaced) and having the engine swapped. Any ideas about where to purchase such a vehicle? Was also thinking about scrapping the car and selling the engine but since I can't take an engine out of a vehicle that's probably not a good option. Thanks for any ideas or advice.