Hey Deborah
I bought a pair of custom made, laser cut & perfectly balanced sprockets with an 18 tooth front (and a colour matched rear for free) in a thicker than standard size (530 sized), and a 530 chain to replace the lighter 525 one (will last much longer) for about 2/3 the price of the Triumph kit. The only thing you lose is the little rubber buffer that the OEM front has on it that's supposed to make the chain run quieter, and that wears out after the first few hundred miles anyway.
You don't mention where you are but I'm assuming you're in the US so my Australian supplier's not going to be any good to you, but I'm sure you can find someone local to you that manufactures their own sprockets who could do the same thing.
Matt
