I've missed that. Do you get a better rate when you're 60?
LCC:
Concessionary membership £14
Annual membership for full-time students, under 16s, over 60s, or those not in paid employment.
CTC:
Senior (over 65) £23.00
Senior '5 yrs for the price of 4' £92.00
Unwaged £23.00
Junior (under 18) £12.00
So if you are over 60 or unwaged the LCC seems the better buy. I don't think there is any requirement to live, work or play in London so if you treat it as third party premium I would seriously consider it.
Returning to the main subject: Would it be simpler to insist that all riders were members of LCC/CTC and rely on that for rider liability? I understand it would not cover Leader/Wayfinder/TEC liability but that is a much lower risk than me just getting too sleepy and running into another rider.
Frankly I think it irresponsible to partake in any massed cycle event without Third Party Cover. Mistakes do happen and we do have a responsibility to our fellow riders that we can compensate them for our errors and not put our own family home/lifestyle at risk.