I have friends who use one rifle for everything too, some buy one box of ammo every few years and kill elk almost every year too. ( I'm thinking of 2 right now, one uses a 308, one uses a 270) I know "more guys/friends) who use milder rounds for coyotes/deer and a "bigger" round for the "Out West rifle or for elk",etc. As far as "budget goes", nothing like the learning curve of a POC to fail you at the critical time. Hopefully this young man will be happy with his choice and it serves him well the rest of his life. Hopefully.