I have a Aim Point PRO, a couple of EOTechs and a couple of Bushnell TRS-25s.
I am running a TRS 25 on a SBR AR15. Low round count but no problems. I am also running one on a M11A1 with Lage Upper on it. It is a FA gun and the TRS25 probably has about 2000 rounds of full auto fire under it. No problems.
The TRS falls into your criteria. No it does not have the battery life or the durability of an AimPoint. But it does cost less than $100.
With all of that said IMO you would be better severed buy a good set of ghost ring sights of your shotgun.
Accurate 100 yard hits are difficult to obtain with GR sights. We where shooting 8 inch balloons at 100 yards with slugs and smooth bore.