assuming your talking about a front and rear bar then to be honest they are simply worthless to all but the guy that has still got a factory one that is dented. 99% of people that have these accessories fitted dont look back over their shoulder for the old parts just incase they are Forced to take them! Disposal rather than Hoard.
Side Steps? Maybe worth keeping and selling to someone that has bent one? Anything else? Junk!
Bumpers, Seats, Radios, even factory Intercoolers are all junk! I might chase the intercooler for spares but the rest is worthless. The Wrecker values them because they are trying to make their money on every part of the wreck they buy, thats the point! but ask them if they want to buy that rear bumper off you for even Half what they want to sell it to you for and Good luck with that! They would say...... I have 20 mate! in every colour! No thanks.
Your Local ARB store would have a Pile of front and rear bars for a GU8 sitting out the back, my local had a big pile of rear Tub Roll bars out of Navaras stacked up, i said mate put them on ebay! he said nah mate thy are junk, i take them off to fit canopies and no one want them, every car has them already so junk they are.
If your talking about the rear Seats (3rd Row) because you fitted drawers? You are welcome to mine mate ;) They ahve been bagged and on the top shelf in my shed for 5 years becaus i cant bring myself to put them on the trailer for the tip. Worthless! Nissan want $1200 for them and the wreckers want $600 but they are worthless and junk to all but a small few.
Dont let it do your head in mate, noone is swindling you, there is not really a business in selling this stuff. ;)