Being rather sad, when I got my current car, expecting to rip through tyres like no tomorrow I spent a bit of time searching through tyre prices and noted a few in a spreadsheet in March last year. These are all BMW marked runflats 225/45R18 and 255/40R18, full set fitted priced on blackcircles...
Hankook Ventus S1 Evo 3 - Now £710, were £714
Bridgestone Potenza S001 - Now £756, were £771
Goodyear Eagle F1A3 - Now £819, were £829
Michelin PS4 - Now £862, were £925
So all a tiny bit cheaper compared to a year ago, bar the Michelins which have come down quite a bit.