What is the average cost for a probate litigation lawyer

To my knowledge, there is no source that would provide that information, although if you search the internet you might find one. Most of the ones that I know (I am NOT a litigator and don't do that work at all) ask for a minimum retainer of $10,000, although there are a few who I know of who may be able to work on a different basis. The retainer is what you put down in advance. The fees and costs could be only a few thousand dollars in a quickly-resolved case, but could end up in the tens or hundreds of thousands in a case that is complicated and that goes through multiple rounds of trial and appeal. The best way to start trying to figure out what a case you may have will cost is to call an estate litigator and get a consultation. That's the only way anyone will be able to give you a real idea of potential costs. Best wishes to you.