So, one of the slightly recent trends that I have come to really despise in the 40k circles is the "trending unit/tactic of the week."
In this case, a few months back after yet another rules errata update, some nerds managed to pull their noses out of their books and declare that the Whirlwind support tank is a good cheap unit to have on the field, and in constant overwatch. This of course causes every damn model on eBay or in the stores to go up in prices or simply disappear quicker altogether.

After spending weeks hunting down STL files, and other avenues, I managed to find a used model that was already painted pretty close to my chapter colors for an affordable price. Yay me.