Tracy,
I have walked in those shoes, and I honestly couldn't think of a "good" time. Fall is bad because we're buying for Christmas, Jan-Feb it's V-day prep, March-May it's Mother's Day buying and those big WS statements, then in the summer sales are slow ...
What I do know is that we're aiming to start delivering even more value in time for V-Day, Easter, Mother's Day and further equip florists to take advantage of the summer lull.
The subscriptions are annual or monthly from the day they are purchased, so there is no pro-rating required (great question, BTW!). You can sign up now or in July - whatever is best for you
Regarding the Strider / FC issue: I strongly believe we're delivering excellent value in both products independent of each other. They are separate entities requiring separate development and maintenance time, and both are delivering separate rewards to the end user. I really can't justify offering a lower price on either. Please know that this was a considered decision, and like most things with FC and F20 not something we entered into without some thought.