Investing in cheaper properties?

[Account Closed]

I'm hoping to invest some cash I have into a few different properties to get some cash flow, and then, I would like to refinance the properties to pull the equity back out and use it to buy something more expensive. I am looking at a few houses that are around $20k, with current long term cash flowing tenants. Yes, they are in a bad/low income neighborhood, but, they also have a good rental history and don't need any repairs.

My question is, if I have, say 4 properties that are worth $20k that I own outright, will I be able to get a normal loan on them later on to pull money back out? I understand that most banks will not mortgage a property that is worth less than $50k. Is it possible to lump them all together and count it as one? Or will I have to find a "special" lender to help me with this?