Seller agrees to carry back financing, running myself thin?

[Joe Doman]

I negotiated seller financing with a motivated seller. The terms are good but I am worried I am taking on too much as I already have a deal in the pipeline. 

Here is a hypothetical: arv is 200k, needs 30k of repairs, terms:150k purchase price with $500 monthly principal only payments for 5 years then balloon.

There is obviously value in the terms... One idea is to assign the contract. (I assume I  can sell this contact to an investor).  How would I determine the value of the contract? How much would you pay for this contract?

Another idea is to get an equity partner to spread the risk but again, I am not sure how I would structure it

Any thoughts are appreciated!!