He is basically living in the Living room, most all the rooms are basically an accumulation of old memorabilia.

Really nifty ideas create a lot of interesting memorabilia, but often no profits.  

They sell for $230,000 and buyers are fixing them up with upstairs mezzanines, lifts, memorabilia and incredible man caves.

As I have always had a flair for antique collectibles and memorabilia, I love the current windows that we have whereas DH wants to get it replaced with new stylish ones.

I know as you mentioned classic cars are a big thing in our part of the country -- could  you start some sort of Guys/Car hangout - use the front office as a clubhouse - lots of old auto memorabilia there and in the warehouse (plus you'd have the fun of shopping for it), maybe install an automotive lift or two, great lighting - fire suppression system (would definitely make your insurance cheaper)? 

I inherited a whole room of Elvis memorabilia.

The house is on a corner lot, it has a lot of old "memorabilia" in the driveway, and the whole property could use a facelift and it would definitely be a bonus for the whole neighborhood.My question is, how do I motivate this person to sell?

You can try selling some of your baseball memorabilia from you playing days.....lol.

This is the same stuff people use to do table tops with memorabilia - eg pennies, bar tops - so it is a very thick layer. 

Note that everything is fair game if you leave it accessible - Fine china, memorabilia,  heirlooms, even your favorite ice cream or personal hygiene items (your shampoos, hair products, brushes, etc are fair game if they are not locked away in the house, Replace them and hide away the stuff you wouldn't want to be used by someone else or broken.7.Make sure you have somewhere to go on short notice and for days at a time.