Search in a price range somewhat below your upper limit -- if you find yourself in a bidding situation, you'll have some wiggle room. At today's low interest rates, an extra $10,000 may add only $40 a month to your mortgage payment. The money will be held in an escrow account and used as part of your down payment at closing. Out of the goodness of your heart, you may not even want to charge them rent, or at least not more than what your mortgage payment will be. Write a heartfelt missive about how wonderful you find the seller's house, how well taken care of it seems and how you will cherish it once it's yours.