If you're looking for PI (provider independent) resources from RIPE, the costs to the LIR (on top of their annual membership fees) is around 50€/year. An ASN and a /48 of IPv6 PI space would therefore clock in around 100€/year (which is in line with the GP's pricing).

Membership fees are around 1400€/year, with a 2000€ signup fee. The number of PA (provider assigned) resources you have has no bearing on your membership fee. If you only have a single /22 of IPv4 PA space (the maximum you can get as a new LIR today) or you have several /16s, it makes no difference to your membership fees (this wasn't always the case, the fee structure changes regularly).

(EDIT: Source: the RIPE website, and the invoices they've sent me for my LIR membership fees)

> All subscribers to Internet access provided by the provider must be members of the provider and must have the corresponding rights, including the right to vote, within reasonable time and procedure.

Not all of our subscribers are members of our association. The association is primarily a hackerspace with hackerspace members being members of the association. We just happen to also be an ISP selling services commercially (eg. to people colocating equipment with us, or buying FTTH connectivity in the building we're located in).