Its one way of doing it I suppose and maybe the way these days.
The simple fact as Genghis has said they are refusing to take payment up has actually limited my warning bells on the price.
To be honest the price doesn't really say anything about the quality of training and your relationship with the instructor has more to do with your enjoyment and amount learned than anything else.
The gliding fraternity have got there house well in order on the training side of things. So personally I would go for a few hours and see if you enjoy the place and the aircraft. It will give you access to very affordable flying in the TMG afterwards.
I would budget for 7.5k though and if it does come in at the price quoted you are well in.
PFT: The MotorGlider Club | Pilot flight training and lessons
Is this the place?
70 quid dual can't be laughed at.
Seems pretty good setup actually if you do go for it let us know what it was like. BTW I would book in quickly if you do go that way from experence on getting outed on pprune schools fill up rather quick when this happens. I went from 12 hours a week to 25hours a week instructing when I was working full time in the space of two weeks.