Messy eater

I'm grumbling about stamp prices. 
I write to my brother in Spain. A letter to Europe costs £1.42, up from £1.35 in March. It's not the price rise that gets me. When the price rose so did the price for 1st and 2nd class stamps. A combination of a 1st and 2nd class stamp used to add up to £1.35, perfect for a letter to Europe. Now a combination of 1st and 2nd class stamps costs £1.41 so I need a 1p stamp to add to this combination (I have a lot of 1st and 2nd class stamps, I don't write to many people other than my brother who is a total technophobe). 
There must be others with the same problem as our local post office is out of 1p stamps and can't get any more. In fact the lowest denomination they can get right now is 50p. 
So I go to the Royal Mail web site and, hey presto, there are sheets of 1p stamps. 25 x 1p stamps for 25p. 
...... Except. They are charging £6.70 for delivery. If I were to put in an order for £50 worth or more I could get them delivered for free. 
So Royal Mail are telling me that it will cost them £6.70 to deliver 25 stamps but nothing to deliver 5000 of them.