Royal Mail increases its Special Delivery Charges

The minimum has gone up from £5.90 to £6.22 – an over 5% increase.  However, because I have a good stock of recycled packaging, I’m planning to keep my charges at the same level of £6.50 per order for the foreseeable future.  I can’t see it lasting after the next round of increases whenever that is.  Maybe I’ll have to look for another Courier?