I was in Sainsbury's yesterday, and they were all out of both types of the cheapest balsamic vinegar (and cheapest green olives too - pretty much a failed trip).
I have it with pretty much everything, and it's brilliant, but I have only ever had the 99p stuff (or £1.29 in flippin' Sainsburys). So anyway I took the plunge and bought one that cost £1.99, and it is actually noticeably nicer, if only a little. Just has a bit more of a kick. Kind of like eating Heinz ketchup rather than Sainsbury's basics, even though the latter is still alright.
It got me to wondering what the bottle they were selling for £18.99 tasted like. Has anyone ever had really expensive balsamic vinegar? Can it really be 18 times better than 99p balsamic vinegar, when this is already pretty amazing as it is? Or is it just Sainsbury's sticking it in there so prententious poshos will buy it just because it's expensive?