I need a new unicycle

I’d agree you should look for a 29" or 36". Coming from a 16" there will be a significant learning curve but November should give you enough time to learn to be comfortable on either if you can put in some miles. I’ve found that on a 29" with 114mm cranks I am able to avg 10mph over several miles, which is only 1 or 2 mph slower than I average on the 36" (but the 36" feels like less work).

One option might be to get a cheap Sun 28" and then add a better seat and shorter cranks, all for way under $250.

It’s rare but a couple have gone for well under that recently:

i need a 36 inch (this one was an absolute steal)