This is not my product, but I did a lot of searching and found this great x-cart Product Feed which is much less expensive than what is available now. I plan to implement it tomorrow.
It is by a company called MagneticOne & they have different feed versions but the all in one has every kind of feed you can imagine for $115! That is so much less expensive than others out there.
Easily export your products to following engines with minimal efforts:
Google Base
Froogle
Shopping.com / DealTime.com
Shopzilla.com / BizRate.com
Generic RSS
MySimon.com (new )
Yahoo Stores (new )
You can see it here:
http://www.magneticone.com/store/X.Cart.Modules...Mods/X.Cart.All.in.One.Product.Feeds