The WBs weigh something similar to those small Zs, plus if you use a sulky, then rutting is not something youll avoid with e WB!
Im currently researching the same thing, Im quite sure now I've narrowed it down to the husky 30", its the only one I can leave the catcher on the back but just removed the chute to get through gates. Its also 100 lbs lighter than the timecutter, lighter is important for me with residential lawns to avoid rutting. My motive for a new purchase is to make work easier in the heat of summer as well as get through it quicker, so man handling a WB isn't going to be a great deal different, actually more work than a 21" SP.
A stand behind would be good, however they are too expensive as you say! I know this is just as expensive but have you looked at the Ferris Evolution, it prob doesn't suit though I think its 36" & you need to get through 36" gates.