Wow. You do way better than me. Pair before last I got probably 100 days out of, but I probably should have ditched them at 80. This last pair only has maybe 60 days on, and I'm ditching them, though I definitely could go another season if I wanted to, but I'm at "last buckle" in a few places and given I only paid $50 for them on EBAY (my best ski equipment bargain to date) I dont really care.
I had/have the same fear, but given my last positive experience, and the fact as has been discussed in this thread that online returns are so simple now, I'm now far less apprehensive.
I lot of my life I was skiing 60-100 days a season. So, I'd try and get 2-3 years out of them. My Kryptons I gave up on after 150ish.
It's not so much returning I'm concerned with, but long term fit issues where a shop can punch things out in places or re-mold liners if needed.
Those services come at an expensive cost if you don't buy the boots from a shop. Typically free for the life of the boot when you buy from shop. I've also gotten buckles replaced for free with store bought boots.
Everything else I typically buy online