.
Considering both new and used...
Not concerned with non-toxic or steel shot...
Just lead...
What is the most reliable semiauto 10 gauge shotgun ?
Ithaca
Remington
Browning
Other
.
Of course, you could also consider a 12 ga. 3.5" semiauto- lots more to choose from, and the 3.5 gives up very little, if anything, to the 10 ga.
Ammo is also a lot easier to find, and is cheaper, in 12 ga.