Note: Alcor is no longer accepting new associate members (according to the page linked to in OP).
For people over 18 years old, membership dues are currently $15 x (age at time of sign up).
Would be great if you could update the post so it stays up-to-date.
Thanks for writing this!
I just contacted Alcor about paying with a trust and they wrote back “Alcor does not accept Cryopreservation Funding Trusts at this time.”
It seems like life insurance and prepayment are the only options.