Check you 'standard" socket set, may be it's an old English bike. Long shot but worth a try before you pay $5.99 for a single 14mm socket at Sears.
Speaking of buying tools, you might think about picked up a full metric set instead buying a single socket. may be you've been wanting some deep sockets. Often times Sears has some great deals going on socket and wrench sets that don't cost much more than paying individually for 2 or 3 pieces.
Check you local fleamarket too. Back when we were poor college kids, we used to buy Craftsman tools cheap at the fleamarket. $1 sockets, that kinda stuff. They might have looked rather beat up, but hey, Sears lifetime warranty don't care where you got it.
As for substitute tools, a gear puller will easily pull your crankarm off. It doesn't sound like that's necessary if all you want is to remove two chainrings. Wouldn't a hex or allen wrench be what you need for that?