Where do you come up with the "15 minutes average flight" ?
Having done literally thousands of them! They are not usually soaring flights and, if they are, then they are not usually that long....Many are flown for groups in non-soaring conditions and in the evenings when soaring has finished....Anyway you know that dont you...
These trial lessons are a "jolly" and invariably a one off, so people pay for it on that basis.
In comparison with power it's pretty cheap to try - Stratford will give you a winch-launched trial lesson for £50, as will Shenington, and the others will launch you by aerotow for £75-£90.
It is that statement I refute...its not cheap to try, at these rates, compared to powered flying!
20 winch launches would cost you around £350,
What? £17.50 each!!!! Even Lashams are only £8.25 (See their website).
UV
mstram..Just seen you are in Canada ...maybe its different there!