Earlier today I purchased a replacement black ink cartridge for my Epson stylus C64 from a local shop specialising in printer ink and was charged £17.
The cartridge was a compatible cartridge by 'JetTec' not a genuine Epson original.
A search on the internet for the JetTec part revealed that the exact same Jettec cartridge could be purchased from
www.kenborne.co.uk for only £6.40 (+£1 postage), while the genuine Epson manufactured part was available for £16.95. Other suppliers www.page-net.com listed compatible ink at &7. Amazon.co.uk listed a compatible ink at £4.70.
I wish I'd checked online prices before rushing into town to pay more than double.