If you can buy a moped for a "few dollars more" it will likely be one of the made-in-china-piece-of-junks that you can find a million of used.
The reason they are so available is simple- chinese QQ in a much more complicated/expensive/just as slow machine. People buy them, use them till they break, then park 'em in the garage.
At least with these motorized bikes, we love 'em so much that they get fixed and right back on the road....for pennies.
I have ridden the soul-less, slow, cheap mopeds, and they do have better brakes (sorta) and vibrate a wee bit less. You do however, have to have a thick skin and really dark glasses to ride one.
If you are gonna buy one, go to Moped Army - Swarm and Destroy