Because I just got mine.
One of my retirement projects was to get into O gauge buildings for an attack on a zombie trailer park.
To that end, I began collecting the buildings (I may post more on that later).
My most recent purchases are two Plasticville Hangers and the Airport admin building.
Here is what I have learned:
1) The best buys are usually as part of a collection of other buildings. My first hanger came with a diner and the Admin building had both a hanger and a two story house.
2) Watch for the best deals. I have been able to make my buys at an average of $10.00 USD or under for each building.
3) At these good prices, you should expect to need to make some repairs (but since you're turning them into wargaming pieces that's part of the fun). Make sure to view all pictures.
4) There are collectors who will charge a premium for unbuilt kits in pristine condition. Along that same line I have found some questionable deals (old box with new models). To protect our fellow collectors, I destroy any boxes that I get to prevent fraud. I will admit I was tempted to resell the boxes.
5) I was in touch with Bachmann (owners of the Plasticville line) and they are currently discontinuing the line and no one was sure of its future status.
Just to give you some ideas I'm including two links to what others have done:
link
link
experiments to find a better way to mount aircraft for wargaming.
