First of all I don't want it, but I might be able to help you with a price.
Is it a used or new tranny? If it is used, is it rebuilt? If not how many miles? Is it the highly sought after 6.x ratio or the common 5.x ratio?
Used Dodge 4x4 NV4500(with 5.x ratio) can be bought from the junkyard network for around 1k. Here is where yours will be different. If it is the highly sought after 6.x ratio...it will be worth alot more(but these were only produced 1 or 2 years). Possibly up to the 1500 that you originally quoted, maybe more if it is rebuilt. If it is this version post it on the POR for sale board and set your price at least at 1500...it will probably sell.
If it is the 5.x ratio...you will probably get less than 1k. The chevy version will requie both the bellhousing and tailhousing(even if 4x4) to be swaped out to run with a stock NP231, D300, etc. They don't match up. If you have this version, you would be better trying to sell it to a chevy owner, you may be able to get more for it. Too much more money(tailhousing) will have to be invested in this tranny for it to work in a CJ, YJ, or TJ.
You either have a jewel or might have to take a loss. Good luck.
OIIIIIIIO'81 Scrambler & '88 Grand Waggie