Often see ink cartridges turning up cheap in charity shops that don't fit my printer. Would it be a simple case of drilling small hole syringing out ink and putting it into my own cartridges. I am assuming the black, cyan magenta and yellow inks are all similar?

There are various ink qualities and properties but the short answer is yes. One thing to bear in mind is that some cartridges have a chip that counts how often that particular cartridge is accessed as a result this acts as a page count meaning that even though it may have been re-filled it may be indicated as empty. If this is the case 'chips' can be bought cheaply enough. I hope this helps.

how any one could be bothered doing this is beyond me, ink in big bottles are super cheap to refill your existing cartridges anyway, I wouldn't want all bits of different manufacturers ink mixing in together

Never done it before so don't know how easy it is to do

If you can find a cheap re-inking kit that comes with individual ink syringes it is very easy (it can be done with one syringe giving it a good clean between colours), just dont squeeze the cartridges or the will be a heck of a mess.

You can buy, for about a tenner, a little device that resets the chip when you fill it. I have never used one, so cannot say how effective it is.

I buy cheap cartridges on the internet at about £2 to £3 each. They seem to work just fine.

Epson is now producing a printer in which much larger ink containers can be used mounted on the side of the printer and linked by flexible tubes to the print head. These contain enough ink for thousands of pages and seems a much better idea than moving cartridges and head about. You are intended to refill these containers yourself.

I'd expect the printer to be a bit faster. A lighter print head means less inertia so it can be moved about faster, but I haven't seen any reviews of them so don't know. Probably worth a look if you do a lot of printing.