Hi Tengu,
If you search on line for mono lazer printer you will get one for c£70 or less.
They will print up to 4,000 A4 pages and the cartridge can be refilled for about £25 a go.
I have refilled a cartridge 4 times with no loss of quality.
They are now doing colour lazer printers for about the same cost tho it will be cheaper to replace the lot rather than the colour cartridge's when they run out.
I suppose what I'm saying is its more cost effective to to buy new and get the ink/toner in the deal than buy/trade for a used one and have the cost of the inks.
Cheers
Boots