Tax delinquent deal

[Jon C.]

I have a deal I'm working on: The house is owned free and clear in DFW. However, there are $40,000 in back taxes. The house was originally bought for $17,500 in 1966. The house will need plenty of rehab. We've prepared comps for the deal, but I've also read about people paying the taxes and throwing some cash on top to satisfy the seller. The ARV on this property is $150,000. What is a reasonable offer? Exit strategy is to wholesale.