Or, you could save some money and use boiled linseed oil.

I just finished treating the frame of my '82 Trek with boiled linseed oil. It's kind of messy to apply, and it tends to drip all over the place, but once it sets, it's like varnish. If you go this route, however, make sure you clean the outside of your frame really well before it sets, otherwise it's a ***** to get off.