How much do you offer for cash for keys?

Hey guys! I just purchased my first property in the Birmingham, Al area out of foreclosure at the courthouse steps. It has been an interesting couple of days. Definitely a new experience! My biggest question is what is a good offer to start with on cash for keys? Do you do a percentage of the price or start with a small flat fee? The property I purchased is in amazing shape outside. It was built in 1945 but has been renovated twice. The first time it was renovated was 1999 and again in 2013/2014. I have set a budget of 25,000 including renovation, lawyers fees, and holding expenses. I know that an ejectment can cost as much as $2,500 so is it worth it to go up to that to prevent property damage, removal of appliances, etc.? Also if you have a great lawyer that you want to suggest for ejectments I would love to speak with them. I have already sent notice to vacate(mail and nail).