Bordercollie, I purchased a 3215HST (same as 3316 except decals) 14 months ago. Like you , I was looking for a smaller tractor to supplement our larger machines. It has been a very pleasant surprise as far as how much this little tractor can do, it has been a good little work horse. Your pricing is right in line, as that is about what I had to pay. I had and have done a few improvements to it to make it that much better for me.
To start with, my dealer installed a canopy, a Mahindra factory rear remote, and exchanged the Mahindra OEM spring seat for a 7520 OEM suspension seat for a minor up charge.
In hindsight, I probably would not get the OEM remote again. Besides it being a little costly, it doesn't work how I feel that it should work. It is a 4 position valve which is good, but when it is in float mode, the 3pt will not pickup.
Not that that has hindered anything yet, it just seems that it is not right, to me anyway.
All the other improvements I have done myself.
I built a "TnT" set, as in fabricated the cylinders as needed to match the factory links. Installed a standard double valve with float position on one of the valves from Surplus Center. Built the hoses myself from parts that I bought from Discount Hydraulic Hose. Installed needle flow control valves on each valve to be able to reduce hydraulic flow as needed.
Installed an ammo box behind the seat and reinstalled the SMV sign, you can barely tell that it is there.
It is a bit tight though, and is easier to open with the seat slid forward.
After contemplating where to put a cup holder, I decided that It would be the easiest to just mount it at the base of the ROPs next to the fender. I used a piece of aluminum to mount a 3" ABS cap to the ROPs.
Mounted a fire extinguisher to the ROPs.
Installed some 5"x 3" lights on the canopy front and rear. Installed some rocker switches that light up when you turn them on. The wife made some decals to put at the switches to indicate what they are for.
Reinforced the loader bucket and installed chain hooks. I used 3/8" plate on the sides and 3/8" 2x2 angle on the top lip before the 4 hooks got welded on.
Changed the ends on the 3pt stabilizer-sway bars where they mount to the tractor to ball ends. Waaaay better.
Here are some pictures that go along with the improvements.
Another note, I have a Mahindra (made in India) 7520 4x4, with over 400 hours the only failures have been the PTO sensor and a sticky brake light switch. The 15 & 16 series tractors are made 100% by Mitsubishi for Mahindra. They seem to be a trouble free machine.