DE blade price?

I posted earlier about buying a double edge razor.

I have since bought that starter pack and used it today and liked it a lot. So thanks for your help in advising me.

I now have one final question. When eventually buying some more razor blades, what kind of price should I be paying for each blade? These blades look quite cheap but obviously I don't know. To add to that is there any brands I should avoid or ones I should look to buy.

To add I'm from the UK so if they could be available to purchase in the UK that would be great. Thanks for any help.