I would recommend you step back and take a deep breath. You are posting on sites dedicated to collectors. Collectors are passionate about their hobby. Some are very vocal about their passion. I already knocked you for your terms and price, but at the same time I believe it is a sample/early production unless someone went to a lot of trouble to fake it. Given the condition of the front decal I don't see why they would have.
At this point though all the samples are pretty much known it is just a matter of knowing where to dig up the info. It is also about how much time you want to spend.
the trouble with IJ is that the samples don't really do anything the production doesn't. With DW you get a moving topper, tz you get a third magnet with a great multiball start, WWF gets you 3 magnets under the pf like taf. Alot of proto's/samples have different art, or something that really sets them apart.
In my case while I have kicked around the idea of getting an IJ (or sttng) and do have a rbion I could trade, I cannot fathom trading my rbion + 3000k or more for a sample with fade. Especially not when IJ's can be had 3500-4k with fade. In this instance you are expecting a 1500-2k premium for lack of a start button, some small metal rails, and a plastic. This is after you have already dropped the price by 1500.
While you are throwing in decals that are worth up to 300 depending on who made them they are a boat load of work to install correctly. It isn't a simple matter of cleaning the sides off and applying a sticker. The cab needs to be stripped of everything, bondo applied, sanded, repeated, decals applied straight, cut the corners without mistakes, holes cut in for bolts without mistakes, and then the entire thing needs to be re assembled. One false move and you need to replace a decal you may not be able to buy outside of the set.
Regardless of what anyone thinks if it is priced fairly in 1 buyer's opinion it will sell. Usually the higher your price something the longer it will take to find a buyer (that isn't always the case, sometimes you price it cheap and no one near you is looking for it). So like I said, take a deep breath and see what people offer.