There could very well be supply issues, neither of the suppliers we use at work can get rain sports, possibly because the have sold all their batch. if you look at your tyres the DOT code will tell you the week of the year the tyres are made, tyre manufacturers dont make all tyres and all sizes all year round the schedule them by weeks, we have been having issues gettign bridgestone RE050As that the mondeos come with bridge stone say they dont have any instock in europe, and wont be making them for several months, when you check the tyres they have a DOT code 4810, meaning they were last made in november 2010, so probably wont be made until November this year. and because of stuff like this if some one has some of these tyres instock and there is a demand then they can charge what they want. Abit like a while ago kwik-fit bought most of continentals stock in the most popular sizes, meaning it was very hard for any one else to get them, and when we could we had to pay through the nose for them, kwik fir were selling them 4 for 3, but the 3 were dearer than normal, but because every one else was gettign charged more kwik fit were the cheapest on the market, selling them retail lower than our cost. iirc they had been cheaper then black circles price for just the tyre.
Also generally tyre prices have went up a good 30% in the last year or so, cost price has went up so the retail price we sell them out goes up to, and because they work as a percentage rather than a set value of mark up it inflates the miderange-premium tyre more than budget/ditch finders.
And as said about the same tyres being more and more expensive, vredestein is a prime example, they used to bo sort of under ground hereos, mainstream hadnt got ahold of them but are very very good and very very cheap, but as the word has got out about them the demand for them has increased and so has the prices, and example is the ultrac sessanta 225/40/18 when i had the c4 i got 2 for £117, then 6 months later the same tyres cost £160 and 6 months later they are now almost £220 the pair.
As said on facebook mate the hankook v12 Evos are a great alround tyre equaly good in the wet and in the dry, either that or tyre getting some part worns but even they have went up in price.
