The grinder, and it is not a close call.
Why
Grind consistency determines whether espresso is repeatable. If one click takes you from gushing to choking, you cannot dial in — you can only guess. No machine compensates for that.
The machine determines how good a repeatable shot can be. Temperature stability, steam power and build all matter, and they matter after you can hit the same shot twice.
A $400 machine with a $400 grinder beats a $700 machine with a $100 grinder, consistently and audibly.
The practical sequence
If you have no machine: buy a good hand grinder now — around $80 gets you something genuinely capable — and use it with a French press or an AeroPress while you save. Your coffee improves immediately.
If you have a cheap machine with pressurized baskets: a grinder will not help much until you also fit non-pressurized baskets. Do both together, or replace the machine.
If you have a decent machine and a poor grinder: the grinder is your next purchase, without question.
The budget split
Roughly even is the rule of thumb. At $600 total, $300 and $300 beats $450 and $150.
The exception
An all-in-one like the Barista Express bundles both below the cost of buying them separately, which is why it remains the sensible single purchase.
Last reviewed 30 October 2026