Clean, stock '06 Raptor's in my area ( Utah ) are selling for $3k. Three modded Raptor's are selling for roughly $3300 - $3500. With your mod's your price is good, maybe just a tad high, but definitely reasonable. If you have an offer of $4500, I'd jump on it for sure.
A little over three years ago I picked up an '06 Kenz built 780 for $5900..........Good luck with the sale