following up: i found a refurbished high capacity toner cartridge on "fleabay
" for £40 (inclusive of VAT and postage). i ran a few test pages, text and images, to check the quality of the toner. on the whole, it is good enough quality for my needs.
so, for what i paid, it seems a reasonable bargain.
i did find instructions on how to add toner to the cartridge if i wanted to do it myself.
i may pursue this path for the colour toner cartridges if the refill toner kit is much cheaper than the refurbished unit though it will be a bit of a hassle to empty the waste drum.