SIG fuel is as good as any other brand. With shipping and hazardous materials fees, it is very expensive to buy fuel online.

There is an RC Club in Pittsfield.
http://www.modelaircraft.org/clubsearch.aspx put in a zip code and search.

If you're not already affiliated with them, you might consider calling the contact number and talking to a local modeler. There may be a local source for fuel that will save you some money.