I buy materials from a co which imports it from China. A lump of it has gone up from £150 to £200 in the last 2 years. Maybe it is down to transport costs rising,, maybe it is because of currency fluctuations which haven't filtered back down. It may be because of rising labour costs in China. All I do know is that companies with huge shops are being squeezed now as they can't compete with the web on anything other than convenience.
Ship bunker fuel has risen from usd 150 a tonne four years ago to usd 700 a tonne today.
a container ship bringing that stuff from china will be burning 30-40 tonnes a day for 6 weeks to get your stuff here