I personally think these trees are ugly, especially the bare ones but there are lots of people out there that seem to be fascinated with the 1950's and 1960's era when these were so popular.
Ebay seems saturated with these aluminum Christmas trees and while the cost has come down over the years they are still kind of pricey. They come in several different sizes, some have pom pom branches, some are just straight, while most I've seen are silver this blue aluminum Christmas Tree brought $150 on eBay.
It does help to have all the branches, the pom pom branches bring higher prices than the straight branched trees. The taller the more valuable and if you find one in any color other than silver you definitely have a collectible of value. The original box is always a plus!
The color wheels are easy to come by as eBay has several reproductions, if you do want to stay vintage be sure to add that to the description in the search box.
While most color wheels only had four colors, this rare vintage color wheel has 16 colors.