Can work with your own website, or start with x-cart's templates, or build from scratch. Accepts many types of payment (major credit cards, banks, and payment gateways). Excellent user community. Relatively low cost.
Updates might be time and effort intensive. Might require substantial technical resource to make it work.
Gold mobile ($299 one time fee); Gold ($195 one time fee); Gold plus ($395 one time fee); Platinum ($1,795 one time fee). 15-day free trial.