The biggest reason to repair your credit is your own finances.
People with bad credit are usually charged higher interest rates, higher down payments and higher closing costs on any and all types of credit.
Not to mention that you may not even be able to get a loan in the first place.
But if you are able to get the loan it will cost you more, much more.
To see it all in black and white check out this credit calculatorthat can give you an idea as to what interest rate you will pay based upon your credit score.