I guess I fall into the type 3 investor. I buy and sell sets to fund my large MOC building. I feel I sell at fair market value, not trying to retire, just help fund my hobby. I have been collecting for 17+ years and have recently (last year+) been selling my sets on Amazon. As stated, the older ones sold well, but it takes a lot of storage space and patience to search for sales and then wait till the sets become discontinued. I guess I justify the time as part of my hobby now. I make a pretty good living, but with kids in college, my funds are needed elsewhere, so this is worth it in my eyes.