where to spend $1800???

i have a friend who really wants to buy my Freedom Arms .454 Casull revolver with a B&L Elite 2×7 scope( my tried and true hog killer). He will pay $1800 and I am considering selling it to him and using the money to get a really nice air gun. If you had that much money to buy what you wanted( without going much over that), what would you buy and why? My 2 criteria are power AND quietness, although I am willing to sacrifice a little more noise for power. give me some suggestions and reasons for your suggestions please. Also, don’t figure in the cost of a scope in the total purchase- i have several that will work. Thanks a lot.