A couple of variables make giving you a quick answer difficult.
1) Your trading in a vehicle and dealers love this, they low-ball you on your trade-in,then they try and get a premium dollar on the vehicle they have, that you want.
2) Mileage and condition of both these vehicles make a big difference in the equation.
KELLY BLUE BOOK on an 06 Nismo crew 4x4 with auto tranny (in my area) and 49,000 miles in excellent condition is at about 20,500 retail.
Average trade-in on your truck with similar mileage is about 8,600.
alright. i have 24,000 on mine. so would you recommend me trying to privately sell it? the offer on this nismo is 18,000. which i thought sounded pretty good. but yea, i don't want to get ripped off too bad by trading my truck in.
I always like to deal with just one vehicle. You probably will do better selling your truck yourself. Nissan frontiers from what I have seen are all over, when it comes to pricing used trucks. I have seen 2 wheel drives, priced higher then 4 wheel drives for similar model years. Go figure. 18,000 seems high in this market, regardless off what Kelly blue book or Nada say. Use them as guides and set the price for yourself compared to other market sources. You never know what they will take.
Not sure about Florida but when I trade a vehicle in I get credit on it's value towards sales tax. If you sell your truck on your own you will pay sales tax on the entire new truck so sometimes the little more you get on the old truck will shrink a bit. If you go to the dealer and speak nicely but not too nicely tell him he can't say your truck has no value but his does. If his holds resale high then yours must too.
I traded my 2008 4X4 LE crew with 42,000 miles for $19000 and they sold it for $20,750.
Hope that gives you a real world rough idea.
The last one was perfect but I like my new one even more.