I spend a lot of time looking at comparable properties, market trends, demand, sales volume, etc..., before I invest in anything.  

Earlier in the year, I had two rentals available, posted them online, got plenty of applications, got good tenants, all pretty straightforward.

Over Improving would be fixing/renovating a property to a point were you will not recoup that capital investment because the neighborhood comparables will not support a value that high.An extreme example would be installing a $100,000 in ground swimming pool and patio in a home in a neighborhood where the homes typically seller for $85,000.

Keep it simple, and offer with them paying their normal fees, as most offers they are comparing against will be structured that way.  

I know my general area I live is expensive compared to most of the U.S. 

Would you guys want to meet up some day to have a chat about the Belgian property market and compare notes perhaps in Brussels?

But these expenses are 100% necessary compared to a lawsuit that would subject my other 10 properties from any negligence from the 1 that may have an issue.  

But compared to other markets I have considered Frederick and Washington County seem to be VERY SLOW.

Your best bet is to call around and present your question to local banks, small local credit unions, and the national SFR buy-to-rent finance companies such as B2R, Colony and Firstkey and compare terms, rates and fees.  

If someone can get a comparable unit for $700, they're not going to pay $800 and certainly not $850.