When is the best time to join the Club

Beginning of a month. Personally, I would wait until you know where things are with touring, re Covid.
I think you can get out and about almost immediately, all you will need is your new Membership number, don’t have to wait for cards or books. (At least we didn’t) Club Sites can look up your number on arrival, CLs should be able to check it, via HQ. 

We have done exactly the same as you Fatbelly.

Re joined at the beginning of Feb and received a free night voucher too, so a bit of a bonus there.

DD taken on the 26th Feb.

The only problem I can see with waiting is that you cannot take advantage of advanced booking. 

We're only possibly talking about less than 1/12th. loss of £54, about £4 or so. Is the hassle worth that saving?

Probably the best time is two or three days before the price increases.

Tomorrow!   

we never let ours lapse as with are able to then plan and book sites 12 months in advance so it won't be long before are looking at 2022 trips, especially at this time when staycation is popular 

Glad we do not have the added pressure of such a decision

It's about a Quid a week to be a member. Is it worth all the fuss? Are people that skint?

In response to my own post, if you join before the 15th each month you lose 2 weeks membership but if you join on the 16th you gain 2 weeks membership. 

Agree, some people have very deep pockets.