NFTs are just another (complex) form of micropayment, and as you observe, both flat-rate subscriptions and per-item micropayments generally lead to poor value propositions. A better answer is a simple innovation in the pricing model, a value-based "risk-free" subscription that adapts to however many or few items you want from any service (or portfolio of services) to set a fair and affordable price. Details in "Risk-Free" Subscriptions to The Celestial Jukebox.