I’m feeling my decks are being a bit priced out of my local games

I play with 3 friends locally. We’re all very casual, and our decks are all just precon commander decks.

I play the Green/White Nightmare Coven deck, and the Blue/White First Flight decks. They’ve been very fun, and I used to do quite well. The guys I play with, one runs a bunch of different Dr Who decks, one guy a bunch of LOTR decks, and another guy the Atarka deck. Everyone except me has started adding extra, expensive cards to their decks and I feel pretty underpowered. I know it’s basically Credit Card: The Gathering, but how do you avoid creep like that in local metas. Like my mate running Atarka now runs Ur Dragon and Ancient Copper Dragon for example.

The games are still mega fun, and I love the guys I play with, but how do you stop your decks becoming outpaced by people buying in cards. Do I just have to bite the bullet and get on Card Market?