Actually....... there is an alternative that most people don't think of but like anything in this world, it comes at a price.
The common complaint is that Lo Range is too slow and Hi Range is too fast. If you are willing to sacrifice some of the speed found in Hi Range, then this is something you can try.
Go on e-Bay and keep your eye open for a used Case drive motor off of a 400 series. I've seen them sell for $50.00 or even less. Remove your drive motor and install the one from the 400. It turns slower than your old one does because of the 16 inch rubber used on the 400's compared to the 12" on your 200 model.
Put the tractor in Hi Range and go plowing or mowing. Your ground speed will be about 25 percent slower in both ranges as a result of the motor swap and your torque will have increased by the same amount.