Interestingly (without taking the thread off topic) it's not always the case as an increasing number seem to like the automation Ebay gives them....but I do appreciate you can sometimes get a bit knocked off...Oelrikon have just had a relatively large increase in rods, somewhere in the region of 10-12% so prices are going to be increasing relatively soon. You're probably looking at between £45-£50 a 5KG pack on eBay.
That being said.. if you find a supplier on eBay always call them first, they'll be happy to sort a better price over the phone because of no eBay charges.