These are the costs for RTM
Week 1 is reduced to 3 packs - costs £49.50 per week
Week 3 is reduced to 2 packs - costs £33 per week
week 9 is reduced to 1 pack - costs £16.50 per week
after week 12 it is up to you whether you take packs or not, but you don't have to have any and you can still go for monthly meetings and weigh in at no cost for the rest of your life if you want, you can take packs again at any time if you feel the need.
You just pay for the packs, not sure about other LLCs but mine will only sell in 7s.