I don't want to have to measure rooms or balance heat flow calculations, etc.Note to OP: don't use these numbers, as they vary city to city, and with size of house.

An interesting contrast to some of my points if I may, to the OP, @Paul C. 

Actually, I have two that are behind right now and I expect them to catch up with income tax refund money (they are behind, but are paying).But, on the other hand, it seems that many people have one of those life events that the OP mentioned.  

If so, how do the actual numbers shake out compared to your projections from you OP? 

Pro-forma of .48 op exp/gross inc (way above market expense assumptions) to give cap ~6.7%4.

OP was only looking for 100k to turn into 200k tho.

I'm thinking the OP has little experience so this doesn't really pertain to him and I hope he'll excuse me for hijacking his thread a little, but I have borrowers that have solid experience and I'd like to get them a better rate/terms if possible.  

Now I know this is not answering the O P's question, but having multiple strategies in the "we buy houses business" is very important in my opinion.It should be a "cash or terms business", when you come in Hard  for all cash or some kind a creative financing offer; whether it be subject to, land contract, or installment sale on Free and clear house. 

Not saying that this is necessarily the case for the OP, just stating that there are times in certain context where I think a buyer needs to suck it up and close as promised instead of trying to re-trade a deal in escrow.

Those won't move.The OP is not wanting to re-sell, but just re-borrow ALL the money he has tied up, each time.In this context, I don't know what you mean by "avoid the $45k homes"?