Perhaps they consider an instructor to be more trustworthy than a lawyer
Now there is an interesting topic!
As to charges, £159 for a piece of paper probably doesn't cover their costs. If you look at a typical business which is buying-in materials, and you take the annual cost of their Purchasing Dept and divide it by the number of purchase orders they issued that year, you will find the cost per purchase order is into 3 figures.
The question really should be whether they should be doing this at all.