Art would be $10-30k. No need to go overboard. Get some exhibits about local culture or something like that. Screw that, get some cool shit made by some online blacksmiths or woodworkers. Put a bunch of placards about the history of the place. Security isn't a big deal if you don't have much of value.

More importantly, make sure this is a passive business of sorts. Works well if you live in or near the same place.