$218 for two shocks isnt bad at all - when I bought the set for my Dodge truck (before the lift) I got them from shox.com - was like $60 a shock - might be diffrent since your's are RV but might be worth a try by calling them and asking.
Not sure if your shock has this but from what I remember they have a Allen key in the top of the shock and then use a wrench to get the Nut off - this is where ther ratchet wrenches come in handy.
PB Blaster (Break Free) will eat just about anything maybe try spraying some of that on the bolt before attempting to take apart if you cant get it apart
2011 Rockwood Mini Lite 2306 - Matt
2004 Dodge Ram 1500 Qaud Cab 4x4 with 35" tires and 3.92 gears, Dynatech Longtube Headers & Fabtech 6" lift + Superchips with shift Tuning
Nights Camped 2011 (37) - 2012 (16)-2013 (2) -2014 (5) -2015(0)
USMC 91 - 95 - F/A-18 Aviation Ordnance