Went to my local Lidl yesterday afternoon to get some of these. They still had quite a lot in, so you should definitely be able to get them near you.
I have a Lekmark Z816 and the cartridges would usually cost a LOT of money... I'd never seen refill kits for them before but Lidl have them for just £1.99.
They have a pack containing 3x10ml bottles: Cyan, Yellow and Magenta (colour) and a 30ml bottle of photo-quality black.
Each kit will let you refil 1-2 times.
Hurry!! While stocks last!! They also have CD/DVD marker pens, 4 for 99p (blur, black, green and red)!!