I haven't done miniatures before. Printed it ultra fine detail with 0.05mm layers. This came as a kit-card with vestigial sprew work. https://www.thingiverse.com/thing:4679744 Fun little project. No glue required and fully articulated. For the grappling cable I use 24 gauge flower wire.
Go for the used Prusa MK3S+. People used to pay a premium for assembled and tested printers. As long as you can get the printer to you without being banged up in shipping it's good. Really shipping would be my biggest concern.
I have a MK3S+ and it just prints. I print for my Etsy shop and don't really feel the need for a backup printer. I have 1600+ hours of printing on it. In that time I've had one nozzle clog and one blob. I do a little dust filter on the filament so i don't often get clogs https://www.printables.com/@Fohn23_807562/collections/641537
I'm totally happy with just the smooth sheet. The textured sheet is supposed to work better printing PETG but I've been able to get perfect PETG prints on the smooth sheet using windex as a release agent.