olePigeon is really on the right track for this problem. I have a Xerox Phaser 6220EN and it has near-LJ4 compatibility. In fact, both over Ethernet and via parallel, you can just use the LaserJet 4 driver with it, as it supports both PCL and PostScript natively. It also speaks AppleTalk.
The model I have was new in 2006, so it may be possible to find inexpensively now.
It also does what I'd call surprisingly well with photos. I wouldn't charge a client for photo prints out of it, but you can use it to get an idea of what something will look like printed, and I used it heavily for "contact sheets" back in the day when I was doing all my photo processing on G3s that were really too slow to just browse through folders of RAWs, the way most of my computers can.
If you print with any frequency at all, picking up a good printer would be what I'd call an investment.
Another option is that most LaserJets and LaserWriters will do dithering and grayscale. They cost a bit more than a stylewriter up front, and the supplies cost more each time you go to buy them, but if you buy an LJ4 or LWP600, 630, or 16/600, you can buy the Xerox 15,000-page cartridge for them. (so, $100 for 15,000 pages or $20 for a hundred pages?)