I think you have miscounted, I count 4....

I know of 3 others

I think the payment plan is better to be honest as i don't think that many people will have a spare 120 quid lying around to buy a season ticket at the moment

Yeah, the payment plan will make it easier to spread the cost and plan ahead.
... besides my credit card is heavily burdened currently with the costs to fix my car before it's MOT... though I'd rather avoid letting the bank benefit from any interest on a balance on my credit card.
I really hope the club increases it's season ticket holders, whether it be the early bird offer or a payment plan, I'd be really interested in knowing the final number at the start of the next season.

I too think the Payment Plan (membership) is a good idea, not only for the fans but also for the club because it gives the club a steady cash flow throughout the whole year.