Hotter temps can be used for soldering or fuse welding certain materials.
As far as temperature ranges, you can get guns from Steinel with a digital range that’s infinitely adjustable almost, for more precise temperature control, and Master Appliance has a gun with a laser surface thermometer for very precise SURFACE temperature control, to prevent over heating a finish when removing decals stickers etc.
Temp range and control needs vary with what you’ll be using the gun for, and what might come up that you’ll need the gun for.
Price range should really be judged by personal budget, and likelihood the gun will get lost, damaged or stolen by some ********.
Also,
You might want to look into tip availability, since having different tips can be very helpfull with certain tasks.