@Alex Smith
This question depends on so many elements. I feel like one has to pick something, study the heck out of it, and jump in. A lot of your question depends on what market you are in as well.
If you want to compound money overtime, I think the classic BRRRR that everyone talks about so much on these forums, will accomplish that if you buy right, and understand each step in the process and what has to happen for you to hit the numbers you are looking for.
I personally think the auction idea would be a nice option, you having a high risk tolerance and all. Buy something for cheap with cash, make sure rents will make the 2% rule (or whatever #'s your looking for), and over budget for the rehab just to be safe. Then Cash-out refi as much as possible of what you put into the property, and roll that over into something else, or payback where ever you got the money.
That is simply one idea, and it can be done in a number of ways. The $50k could be used as a down payment on a distressed multi-family, for example. If you have some experience this might be a better option.
I tend to think the market, in general, will be stabilizing soon but markets are so localized. A lot, I think, depends on what your market is offering you. Kind of like if you were a quarterback and you had to audible in the middle of a snap count, in order to read the defense and call the play to match what they were giving you. Real estate is much the same way. Maybe a flip is in your sites. Buy a cheap, in distress, property with cash and budget a rehab that makes sense with comps in the area for an ARV, make the profit on the sell and roll it into another.
Basically you have options it all depends on your game.