WEll, if I already had all the guns that i already have, and I had to spend that much on more guns...
I might buy 20 mosin nagants ($90 each, all over town), and try to revive communism.
I might buy two dozen break-open single-shot 12 gauges ($75, all over town), and try to revive redneck-ism.
With either of those, I don't get much quality. I could get one nice benelli shotgun with all the trimmings, for a little less than 1800. But then it would only be one shotgun. Or, I could go for a middle road, and get a few stoeger model 2000, which is almost the same functionally as the benelli model 2, and I think I could get four of them for the 1800 at my favorite gun shop.
Historically, I have tried to get the most high-end gun I could get of any particular variety (AR platform, shotgun, Classy hunting rifle, etc.), But I'd like to have more "beater" guns, where I'm not so concerned what happens to them. So I'd either by a set of rudimentary semiauto rifles (SKS maybe), or else I'd invest it in that Vulcan 25mm anti-aircraft gun I've been wanting (but it would probasbly cost a bit more to go through all the process of transferring it). I hate red tape. What I really need is an "anti-ordinance" weapon.