Who says it is owrth $225,000? That is the big question here. If you are working from what some website says it is worth or a county tax evaluation, those are not accurate representations of value. If the house is worth that much, why is this guy walking away at this price? Makes no sense......
Anyway, if you do indeed buy this house as stated in this scenario, most banks will do a home equity loan up to 80% of the real market value. So, if your income supports it, yes, you could get a $25,000 HELOC.