If you have a Boots card, it might be worth shopping in the Jervis Street branch on Thursday afternoon - from 3pm until 10pm they're giving 1500 extra points if you spend €75. The razor would make up a chunk of that, and you might find some other odds and ends to make up the balance. 1500 points = €15 worth of products in Boots. (Although if you've already spent €75, it might be a while before you'd need to spend that €15!)
By the way, if it's just blades you're after, I'm pretty sure I heard one of the street dealers on Henry Street flogging them at 2 packs for a tenner ...