At the moment GT85 id on offer here in the UK at Halfords. You can buy a tin for £2.49 - half the normal price.
I bought four tins for just under £10 and it should keep me going for a while. I seem to get through them quite a bit, probably as I have two Brompton bikes to look after.
I am not sure how long the offer is on for so if this is your thing get it while it is still available.