What's the cheapest basic sainsburys item you can buy in a glass jar?

Bit of an odd one, but I'm a crafter and always need things to store embellishments etc in, but when you go to craft stores for storage containers everything is so expensive so have taken to trying to find alternatives in the form of jam jars etc.

The cheapest I've found so far is a jar of sainsburys own lemon curd for 22p. Great price, but now on a mission to find the cheapest :)

Tough rubber flooring made up of 80% black recycled rubber and 20% colour EPDM (ethylene propylene diene Monomer (M-class) rubber) granules.
http://rubberfloorings.co.uk/gym-recreational-mats-weight-training-areas