These cartridges are refillable as they are not chipped.
You could try your hand at refilling by getting a kit from Asda for about and you can refill both cartridges 2 or 3 times with each kit. I refilled my Lexmark cartridges about 5 or 6 times each before renewing them. The trick is to refill them BEFORE they actually run dry and thus avoid burning them out because they have air where the ink should be. It's well worth a try and think of what you could save!!!
The following site will give you full instructions regarding the 10 and 26 cartridges.
http://www.stratitec.com/
Incidentally, with my last HP printer I refilled the same black cartridge for 30 months and then the printer itself died on me. Shame!!!