Should you buy a 512GB Mac Studio for Local AI? I ran the numbers before ordering one. 1) On token price alone, renting wins. At DeepSeek V4.1 Flash API rates, the Mac needs years of 24/7 output to pay for itself. 2) Price per token is the wrong way to judge it, though. In expensive housing markets, renting is cheaper month to month than owning, and people still buy for control and because a home holds value. The same logic applies to this machine. 3) It holds value. The 512GB M3 Ultra now resells for about twice what it cost new, because memory got scarce. If mine resells for even half, the real cost halves. 4) Nobody can take it away. API models get swapped, rate limited and refused mid-task. In June, access to two frontier models was cut off for almost three weeks. Weights on my desk stay put. 5) Zero-cost tokens change what you build. When every call costs nothing, agents can run all day and you can experiment freely. MacStories ran local agents 24/7 for 99 days at zero token cost. 6) It runs the big ones. DeepSeek V4.1 Flash (552B) and GLM-5.3 (744B) don’t fit in 256GB. In 512GB, each loads into one memory pool. So if you’d use it a few hours a week, rent. If you’d run it all day the moment it was free, buy. Go Local AI!