I rent out a house that is totally paid for and I use the rent to pay for the mortgage of the house I am living in.I don't have any extra cash right now and budget is tight.That being said, what are my options for leveraging the paid off house to purchase another house?

The extra $70k is your fee, and he'll probably need to come out of pocket for that because a bank isn't likely to finance an assignment fee. 

It's almost like putting extra payments into your mattress and then pulling it out in 2044 and exclaiming that you have EXTRA money. 

Some extra info would helpYou state raw land.

You said you don't want to view this deal speculatively, that being the case cash flow is king.As an aside, I would consider renting the garages out separately, or include them with the units as an optional ~$150/month extra.

We had it listed for 1250 per month but rented it for 1600 per month to a couple who's house exploded in a gas fire and insurance is paying extra because of the short 6 month lease.

If you find what is in your criteria, and feel it is a deal it may be worth spending the extra 150$ to turn on temporaly.

This provides extra protection for non-payment and potential damage.

I notice on the BP Rental Property Calculator there is a field for "Other Monthly Income" and the question mark icon gives "extra storage" as a possible example of such other income...I have a 3BR / 2.5BA Townhouse for rent @ approximately 1600SF with an 800SF partially finished basement.

While this may seem inconvenient, I actually get 1 full month of extra rent/year this way.