Is there a grinder under $100 that is not a waste, or should I keep saving? Grinders

For filter and immersion only, under $100, a hand grinder with steel conical burrs beats every electric option at that price and it is not close. The electrics in that bracket are blade grinders or very coarse burr sets with a lot of fines, and fines are what make a french press muddy. Sixty seconds of cranking for 20 grams is the entire cost.

The upgrade you are actually buying at that price is not flavour, it is repeatability. Pre-ground is a fixed unknown; a burr grinder means you can change one thing at a time and learn what your brew responds to. That is worth far more in the first year than any specific grinder in the bracket.

Mild disagreement with the wait-and-save crowd. I saved for nine months for a nice electric and in that time I drank nine months of bad coffee, which is a real cost people never put on the ledger. Buy the hand grinder, use it for two years, then sell it for most of what you paid because they hold value absurdly well.

Second-hand is worth a look for electrics specifically. People upgrade constantly and a well-kept older mid-range electric burr grinder shows up regularly at around your budget. Ask the seller to run it once in front of you and listen for the burrs touching — a metallic ring at zero means the alignment or the burrs are done.

Terse: buy fresh beans first. A $30 grinder with a bag roasted last week will beat a $300 grinder with a bag roasted last spring, and if your budget is tight that is the higher-leverage change.