I'd go for the full $2500, not just $1500, and it would be toward a Flowing Hair Dollar that I have yet to acquire.
Off the top of my head a common date St Gaudens certified MS-65. However, I wouldn't doubt it but you probably have to choose from Littleton's inventory and as we all know, their prices are inflated which, in reality gives you less than $2500. I know, don't look a gift horse in the mouth...I went ahead and entered but opted out of marketing emails.
I decided not to enter b/c I don't want to "like" a company I really disapprove of. I've seen too many collections containing items bought from Littleton that were at least 10x higher than you can get the stuff any day on eBay or from reputable coin sellers. Littleton's stuff is always graded accurately or even undergraded, but the prices are out-of-sight.
I don't do facebook either, but the rules state "Potential winners will each be contacted by telephone, email, regular mail or overnight mail." So, you don't need to do facebook to enter and/or win.