there are cellular based routers that work with Verizon which aren't too expensive. It's really dumb to be in retail and have just one Internet connection for payment processing. You'll call your ISP and tell them your connection is down and your business depends on it, and they won't care unless you have a business class service, like a t1 or better. You'll be one of many with the same issue, waiting.. unable to do half or more of your business.

You could also install cable if you already have dsl, or visa versa. Don't get 2 DSL lines, as they will both go through Qwest in the last mile.. (in 99% of Colorado).