I'd say the following are 
needs in my book on any stock RZR I've had:
- Cage 
			 
- Seats
			 
- Harnesses 
			 
- Steering Wheel
			 
- Full Doors (or lower door add-ons)
			 
- Lighting
			 
- Supporting Wiring to do ^stuff right 
			 
		The following are 
must haves for me but not necessarily "needs":
- Comms
			 
- Fresh Air Pumper 
			 
- Shock Work
			 
- Clutch Work (in some cases, this does fall into "needs" but I put it here to be conservative) 
			 
		The rest are definitely just "wants":
- Exhaust/tune/supporting mods
			 
- Cooler and Storage solutions
			 
- Door Bags
			 
- Wheels/Tires 
			 
- Ride Command dash in non-RC models
			 
		When I say $20k min into any of my RZRs, note that none of them had aftermarket arms, aftermarket shocks (just springs/shocks/real cross overs/valving), stereos, windshields, or any real bling.   Obviously the built Z1-swapped XP4 I bought used had all that extra stuff (other than stereo) but that's a different story. 
$20k goes REALLY quickly just doing the basics. 
Unfortunately, no.  This is exactly why I sold my Funco, at least the Speed is a much smaller chunk of $ just sitting there collecting dust. 
-TJ