Cheap: TRS-25
Expensive: Aimpoint T1
The problem with the TRS-25 is the battery life. Although the battery life is a constant-on 130 days, unless you're keeping counts by the hour, how do you really remember how much you've used? With the T1, you automatically change every 5 years; there is no guess work because the battery lasts 5 years constant-on - you are guaranteed that the T1 will work during that 5 years regardless of how often you use it.
However, since the optic will go on a restricted range-only AR15, then absolutely the TRS-25 is the way to go; you'll never be in a situation where you bring it to the woods for self defense against critters and the optic will suddenly run out of battery. I think any time you are relying on a battery operated device, then battery life should be ranked #2 on the list of requirements. Rank #1 is price. In the cheap and expensive range of prices, and having #2 requirement being battery life, nothing beats the TRS-25 and T1.