I had the opportunity to visit several stores that sell guns as well as an actual real gun shop, a good sized one with fairly excellent prices. In fact, some of the best prices I've seen in Texas in a long time not at a gun show. So El Fisho Jr. and I spent about an hour inside this large gun shop browsing then visited a Gander Mountain and an Academy Sporting Goods store. Although I bought some fishing stuff years ago from GM, I've never taken the time to visit one of their stores, preferrring Cabela's and Bass Pro Shops. GM had a decent selection of both handguns and sporting arms and even tactical arms, and a few good prices.
Academy has some good prices and some selection but this particular store had a lot of empty spaces on the racks. Academy generally has good handgun pricing but suffers from the Wal Mart deal of having the same exact handgun stock in every store, which is great if you want a Glock 9mm or 40 or a Taurus Judge or Public Defender and so on. The same old tired stock of guns. Very tired. They need new handgun buyers.
So I have seen some combo shotgun/rifles so I know they exist. It's just a matter of stumbling upon the right dealer of used weapons who has one or more in their stock and who has them quasi-reasonably priced.