Briefly, yes... you should buy it.
It is (barely) within your $3,000 budget. It looks like a properly designed Hawken, with all the right lines. Nelson is a reputable builder. The parts are of best quality, and the Goodoien barrel is a real plus. The late Don Stith offered Goodoien barrels with his Hawken and Dimick parts sets as an extra-cost option.
Some of the features are subtle. The barrel is tapered, for example, as almost all original Hawkens were. The barrel channel is evidently bedded, which will reinforce the forend but also ensure repeatable seating of the barrel when it is removed after cleaning. I don't know what they mean by the "swept" hammer, but they add that the Hawken Shop locks are copied from originals, so it is authentic.
Oddly, I don't see any mention of number or configuration of the grooves or the rifling pitch (rate of twist). Funny that they would overlook that. However, they make it clear that this is a barrel intended to shoot patched round balls, and I have no doubt Mr. Goodoien chose the appropriate twist and groove depth.
Does the rifle fit you? I am short, and the industry-standard 14" LOP is just a little too long to be comfortable. However if you are over 5'8" or so, it should be good.
Track of the Wolf is an established and reputable dealer, with a solid return policy. If you get the gun and regret the purchase, you can return it.
This rifle is not a "steal." It's expensive, and it is new and unfired. If you want to resell it at a later date, it might be hard to recover your full investment. However, you're not buying it to resell, you're buying it to shoot. It has everything you want and it is within your budget. To paraphrase the old mountain man, "Ho, Smokey, thar's the rifle and thar's the mountains. Shoot sharp's the word."
Notchy Bob