At a purchase price of $225k, at a rough estimate, your mortgage and tax expenses I'm guessing will be about $1,000 if you put 20% down.

My handyman gave me an estimate for $1,500 to pull permits and $4,000 for the work.

The mortgage includes rehab and the estimated ARV would provide that initial investment plus a lot more.

Not too late - when you sign the Loan Estimate is when you've formally engaged and selected the lender so before that you're fine.

We are estimating that we'll need 12-15k for total cosmetic rehab.

They aren't the ones that get hurt if you can't actually afford their estimates.

There are services online that help you estimate repair costs using a PDF of your home inspection report.

Your expert instructor and co-host of the BiggerPockets Rookie Podcast, Ashley Kehr, will cover topics like:Real estate investing strategiesChoosing a market & finding dealsFunding dealsAnalyzing deals & estimating costsMaking offers & negotiatingProperty managementSound like the lifeline you need to make your first deal? 

The repair estimates are taken out of a thin air as well.

Feel free to reach out if you need help with estimating the cost for a 1-4 unit property in Nashville.