How do you estimate if you can't see the inside?

[Amanda G.]

I read an outdated book that had a rule of thumb for estimated $/Sq ft for renovation costs. Does this idea seem legit? How do you estimate when you can't get into the property before you make a bid?

[Ryan Monier]

Assume the worst to be safe!

I would not recommend doing so if you're new to investing unless you have some insider info on the property.