So would you rule out the purchase of the new 2100z over the used 3100z? You feel the 3100z is that much better of a machine to purchase the older / used machine over a brand new 2100z. These are the prices I recently received on the 2100z:
Ferris 2100 BS S-5901343 32HP 61" Deck - $8699
Ferris 2100 BS S-5901344 28HP 61" Deck - $8200
Ferris 2100 BS S-5901346 26HP 61" Deck - $7899
Ferris 3100 37hp Kawasaki EFI, 61" mower (40 hour demo machine) - $9500
I don't have any prices on the 3200z since I wasn't even considering this model until the 3100z came up for sale on the used market.
The 3100 is a true commercial grade machine, where as the 2100 is considered to be much less of a commercial grade than either the 3100 or 3200.
The 3100 with the BB Kawasaki drinks gas like a funnel, and I personally own and operate a BB Kawasaki. I would get the price on a 3200 with the Vanguard 37 hp EFI just to see what the difference may be.
You are the one that will need to make the decision, I personally don't cut corners and buy what "I" want, no matter the cost, and if I were buying tomorrow it would be the 3200 with the Vanguard 37 EFI, you get all the power while saving 20% of the fuel used by the carburetor version.
That is really a good deal on the 3100 with the BB 36 hp Vanguard for the fact it only has 25 hrs. This engine will use more fuel, but not as much as the BB Kawasaki.
This is your money and you need to spend it on a mower that best fits your need.