I think that I have seen them at Penn State and maybe a couple other places. I do not remember the price, but it is not exactly cheap since it requires that you buy both a DC motor and a variable voltage control. The control box is cheap, but the motor, as you might expect is the major cost of the unit.
The variable speed control is fine if you only turn small things like pens, bottle stoppers, and pepper mills, but be prepared for a lot less power especially at the low speed end. You might possibly be better off price-wise by selling the one that you have now and buying a variable speed mini lathe.
I have not tried changing belt positions on he Delta mini lathe, but I have no problem at all changing belt positions on the Jet mini and I have large hands also.
BTW, you might consider using normal sized type. If anyone is visually impaired, their browser can be used to scale type to whatever is necessary.