Mark, you might want to consider altering your post title to indicate the 1:50-1:55 scale of the vehicles, since there are some who say they'd like more vehicles in something closer to O scale than the typical 1:43 types.
While some may like more American based vehicles, I suspect these are made from existing dies and tooling. When you look at prices of these sorts of 1:50 trucks from other places, the retail costs are usually considerably higher than what Menards is offering here.
If Menards to undertake the investment for brand new tooling for similar scale American sorts of vehicles, I would guess the prices would also be considerably higher. Retail prices not only reflect production costs, but the recouping of new tooling costs also. Burger King may have said "Have it your way," but they also sell millions upon millions of burgers. The 3-rail market is considerably smaller, and the scale 3-rail market is even much smaller than that. Companies that don't make money, don't stay in business... and we've seen evidence of that in this hobby.
From the illustrations here and on the Menards website, these appear to be very nice vehicles for the cost. And then the closer to scale size to boot is an added bonus.