4 dollars a gallon?

It seems that fuel pumps are up against another limitation, that of $4/gallon:

The price gauges on some mechanical fuel pumps don’t go higher than $3.99, but the price of diesel has soared way past that, forcing some gas stations to shut down diesel pumps while they figure out what to do. Washington state has a solution: Stations can sell diesel by the half-gallon, as long as they post big signs.

Uh. Right, but I say “another” limitation because, well, didn’t we do this once before? Back in the day when gas prices quickly cranked up from around 30 cents a gallon to 60, and 90, and on to a dollar... the pumps couldn’t register more than 99.9 cents per gallon (who’d ever have thought they’d need to, back then?).

And what did we do then? Some gas stations were priced by the half gallon, imagine that. And yes, they posted big signs then too — though they hardly needed to; no one really thought they were getting their gasoline for fifty two and a half cents a gallon, when the going price was more like a dollar five. (Other stations calibrated their pumps to litres, which also worked but was decidedly more confusing to us non-metric Americans.)

What I find more puzzling, though, than the fact that someone thinks that Washington has come up with some mind-bendingly novel and newsworthy solution... is that the problem exists at all. Once we added a dollars digit to the price, why on Earth did we limit it to 3?

Do we never learn?