Why would you limit it in any of those ways? Maybe you are thinking of the Mares 2S, which is a piston reg mainly meant for rental fleets?The Mares Rover 15x is on sale on LeisurePro for $209.95. For 15-20 dives a year in warm water down to 90ft max it would make a great first regulator, no need to go more expensive in my opinion, at least for now.
The 15 is internally identical to the 22 which has been dived to 313m (yes meters). The current seat and poppet materials are shared with the 22x and 52x and are expected to last at least 2 years or 200 dives before needing replacement. Finally, although metal second stages would be preferable for true cold water diving, these should work great in anything above 10C/50F. There's a cold-water kit available for the 15x if you want to go much colder, but you'd probably want to switch to Abyss seconds at that point.
IMO, almost all Mares regs are great quality and really underappreciated. The exceptions are the gimmicks they've added on for marketing purposes like the adjustments on the Fusion and Epic Adjust seconds. The only real problem is their hostility to self-service. Thanks to the internet you can get service kits for everything, but other parts have to be ordered through dealers who aren't supposed to sell them to end users except as part of a service or repair.
Edit: After I posted, I re-read the original post in this thread and realized Sifossifoco was referring to the OP's needs, not any limitations on the reg. I'm leaving this up in hopes that the info is useful to someone.