I think you may have missed my point.
Most people don't go around swapping calibers or barrel lengths on airguns that have that option. But with these options, are a higher resale value, if you decide you want something else down the road. I bet I'd sell my Maverick at 75% of new a whole lot faster than I'd sell my Bulldog at 75% of new.
Who cares if you can get a cheap gun, if you have to mostly keep the tune the gun gives you out of the box? Tofazfou
did a review of the gun in .357, and he damn near had to rebuild the entire gun before he was able to get it to perform as he desired. Swapped out the barrel with a custom machined TJ barrel, drilled the transfer port, and a whole bunch of other work. I bet when it was all said and done, he spent more than an Impact .357 would have cost, and the gun that he has is a one off. How long did all of that take to accomplish?
If you are happy with out of the box performance, then good one you. But this hobby has a boatload of people that like to tinker, just like motorheads liked to drop a twin turbo and Nitrous bottle into a VW Beetle for the ultimate sleeper. It's just a massive part of the culture.