Look, it's unwise to ever purchase anything without at least thinking about the fact that you may have to sell (or want to sell ) one day. That's just part of the game.
That's a pretty good price for a AVRI Jag (depends on the color, really--that's an important factor, some go for less). BUT.....not such a great deal if it's shady.
Any decent music shop will unscrew the neck for you to check it. You will likely find a barcode and markings if it's a real AVRI neck, or a maker's mark (Mighty Mite...Warmouth etc) if it isn't.
The decals shrink, but they are under the finish, and won't look at all like a badly applied waterslide, which will always have an outline to it, and some depth.
If the difference between this and a legit one is only a couple hundred dollars, it might be worth taking a pass. While you might be cool with a sketchy guitar, remember----plenty of others will be much more discerning and that will hurt the resale value.