I would love to see some affordable scale models ($50-100) of two-, three-, or four-dome steam-era tank cars.
............but I'd still like to have a well-detailed scale car without having to find, pay for, and convert a 2-rail brass model.
If you look around and are patient, you can find brass cars within that price range, I picked up one at the Chicago meet in March for $40. The only ones that I have ever paid more than $100 for have been the high walkway cars from MG or Yoder.
However, as far as I know, 4 dome cars have never been produced or imported. Might have to think about scratching one together just to have 1,
I will confess that I find some of those more unusual chemical tank cars quite interesting.