last time I bought it I paid £21+ vat (total spend of £200), but that was several months ago, and I've heard that steel prices have gone through the roof lately.
I don’t actually know where the supplies of steel are coming from these days, but I would make a guess that it is not all produced in the UK.
With that in mind, and the almost constant move upwards in steel prices over the last few years, I am wondering when and if we will ever benefit from the cheaper imported steel. I suppose that while there are still large demands for steel in developing nations like China it will be a while before the price drops unfortunately.
Don't just ask them, take the price you have, knock a bit off (a few percent) and ask them to beat it. Prices are flexible - you'll be getting a FAR worse price than someone who orders all the time from them, so there is significant margin for them to reduce the quote. Play them off each other. If you just say 'how much is x?' you'll never get anywhere.