I provide 1.5 hour lessons. I believe this is the optimal lesson length, as based on my experience 1 hour is too short to achieve enough whilst 2 hours can be too mentally exhausting for some.

An individual 1.5 hour lesson costs £56 (for comparison purposes this is £37.30 per hour). 
If 7 or more lessons are purchased in bulk, an individual 1.5 hour lesson costs £54 (for comparison purposes this is £36 per hour).

On test day, I charge for a 2 hour period. This includes a warm up drive prior to the test plus the time for the test.