Get your taxes done using TurboTax

2002 I bought the property for $7500. No house on it. Bought plans and went to the bank. They appraised the home at around 185,000. Good friend of mine was a builder and advised me along the way. First Bank had the construction loan. After the home was completed , Wells Fargo did the mortgage. Financed $116,000. I put down about 30,000 to 40,000 down. Total build was in the 160,000 to 175,000 range. Paid for other things out of pocket. This is a vacation home now because I didn't want to sell it. Thinking of selling it now. House is valued at around $525,000. If I sell it , ( and I believe in paying the proper amount of capital gains ) how do I prove to the IRS that the original basis is in the 160,000 range?