I had to pay £3 postage on my membership this year and last year. There was an option to pick it up at the stadium for free, and I considered it, but laziness prevailed. I've previously done click and collect for a match top.
Last year I had Gold. This year, as I am on the Season Ticket waiting list, I opted for "Season Ticket plus", which counts as a Gold Membership, but also allows you to do some extra stuff to do with your Season Ticket if you ever manage to get one.
Ironically as soon as you join the Season Ticket list, the box office web account calls you a "season ticket holder".