How much should I budget for unknown repairs and other unanticipated/unexpected costs?

I expect they will, the other unknown is will people feel more comfortable staying with a corporate entity or an AIRBNB?  

As Ellis San Jose mentioned, anyone who thinks the worst case scenario is that they'll receive 2/3 or liquidated proceeds is incorrect.In dealing with a pre-probate scenario, the decision must be made if you intend to buy the asset, buy heirs' or beneficiaries' interest, or merely focus on plays that make a profit.If you buy the interest(s) and probate the estate yourself, you become the PR and have the exposure to all known (and unknown) heirs and creditors as the fiduciary.

Again by asking around, you can find out how much.Asking about the marketability of land at an unknown address with vague parameters is a bit like asking how much a car is worth. 

Is there enough cushion with your purchase price and estimated repairs to allow for unknown issues and still get in under that price point.

I feel like I am at the point where I am ready to step off the cliff and into the unknown with my first property. 

Sometimes, big sometimes, the unknown is the best and most opportunistic option.

Not being able to turn on the power could be due to the property not having a main disconnect so the FSM could not check with a generator or a wiring/breaker issueI buy HUD homes for a living and my best advice is to only buy at a price that it still makes sense with the unknowns. 

Fewer unknowns.  

That would theoretically be the biggest unknown in this scenario.