seeking shopping advice for laser cartridges

I picked up an old Epson ActionLaser 1600 a few months ago that was destined
for the trash. I've gotten at least 50 pages out of it so far, but the
cartridge is nearing empty. I've pulled it out and tipped it side-to-side
to distribute the toner, and this works for awhile, but the end is near.

I've never personally been responsible for a laser printer before. So, it
was with shock & awe that I went shopping for replacement cartridges. I
thought the first one I saw for $135 was high, but then I saw two other
websites selling it for more than that, one was over $200!
So, asking for advice from my esteemed colleagues here. Are refill kits
worth the time? Found one that does a full refill of the cartridge for
under $24. I'm leaning towards this, since the printer is old anyway, and
really good deals can be found on personal laser printers if you're
patient. I'm certainly not going to spend $100 or more for a cartridge on
this old printer.

Interesting side note: The site from which I quoted the $24 refill ket
warned that "Toner cartridges can refilled an average of 2 times before the
print quality begins to deteriorate." Why is that?

Does anyone have a favorite site they like to use for laser cartridge/toner
supplies?

TIA,
Dan