Grobag here too. If you google for Bambini Pronto, they have them on sale sometimes. You may have a limited choice in colours/sizes, though.
That's where all our Grobags have come from - got quite a few bargains. Also, if you have a Baby's R Us (Toys R Us) near by, keep an eye out for their sales. When they have 20% off baby items, the Grobags are on sale too. Sign up for their emails as they often have sales.

Also, be careful that you don't get a travel one by accident. We did with one of DD's first Grobags and IMO, it wasn't that easy to use in the carseat so it wasn't worth the extra $$.