If I'm reading right... you made an offer of $252k on a home with the concession the owner would gift you back $7000?
If that's correct, your mortgage will be for $252k. Basically you do this to vastly reduce the amount of cash you need to cover at closing costs by building that money into your mortgage... you pay an extra $50 every month on your mortgage but didn't need $7 grand at closing and your down payment only goes up a few dollars (3.5% of $7,000 is only $245).
It's generally a pretty good idea, especially with how low interest rates are right now. I know back in 2004 we actually got into a house with no money out of pocket... 0 down payment and $10,000 back from the sellers to cover closing cost... the home still appraised for $30k more than the mortgage amount... I think those days are over!