Balboa Mist is a lovely soft greige — warm enough to feel cosy, grey enough to stay sophisticated. The catch is Benjamin Moore isn't cheap in the UK, partly because it's an import. The good news is you don't have to compromise on the colour to save money.
Dulux Egyptian Cotton is the standout. At ΔE 0.7 it's an imperceptible match — sit them side by side on a wall and you genuinely couldn't tell them apart. LRV 64 versus Balboa Mist's brightness puts it in the same light-but-not-stark territory, so it'll behave the same way around a room. You'll find it on shelves everywhere and it's a proper budget saver.
If you'd rather a slightly different finish line-up, Crown Recipe Book comes in at ΔE 1.3 (LRV 65.7) — still well inside "very close" and a touch brighter, which can be handy in a darker north-facing space. And COAT Sweater Season sits at ΔE 2 (LRV 62.7), so it's marginally warmer and a fraction deeper, but still a very honest match if you like COAT's low-VOC, water-based formulas and quick delivery.
The "but what about" here: people worry a cheaper paint won't *look* the same once it's on. With a ΔE under 1, that's not your risk — the colour is the colour. What does change brand to brand is finish, opacity and durability. Benjamin Moore's coverage is genuinely excellent, so on a tricky colour change you might need an extra coat of the budget option. Factor that in, and it's still cheaper.
My advice: order a peel-and-stick or a tester of Egyptian Cotton, tape it next to your Balboa Mist reference, and view it morning and evening before committing. Greiges shift with the light more than most, so the eyeball test on your own wall always wins.