A little confused

[#1]

For the first time in many months I've logged into the PN website (been v happy with the product so never had to bother before!) to notice the 3 new products. I've read Mand's summary but I'm still a little confused.
I'm on BBYW2, so a monthly contract paying £14.15 a month (I have 1 referral discount), however I barely use up 5Gb usage a month, let alone the 10Gb that the Value package offers. At £5.99 a month for 3 months then £11.99 it seems like a bargain and would definitely save us some money, however I've been looking for the catches.
Am I right in saying that it's a 12 month contract, or 18 months if you take up the hardware option (which I wouldn't)? Does it move onto a rolling monthly contract after that? Also we'll most likely be moving at some point in the next 6 months and I'm not sure if the cessation charges are still in place or whether we'll be charged more if we move.
My ideal situation is staying on a monthly contract, not attracting anymore fees for changing products, but ideally moving to the cheaper product as we don't use the 15Gb that BBYW2 offers.
Help! 

[#2]

Hi there, you can have a 12 month contract. As for the house move, I can't tell you but, I suspect that were you to move home - having taken on one of the new products - that you would have to pay for the months left. Not a good idea really for you.

[#3]

Ok thanks, I'm also on a "Market 3" exchange, which is one of the cheaper ones apparently. I haven't a clue what that means to me, if I'm ultimately going to lose out because I won't be on a monthly contract then I guess I should stay as I am!

[#4]

Assuming that you would retain any discount I will ignore it...
If you are Market 3 (and your new home is in Market 3) then for Plusnet Value the price stays at £5.99 pm throughout the year. 12-month contract =£71.88.
If you stay on BBYW2 for 5 months or more at £14.65 pm then you will pay more than that.
Whether or not a change of product is a good idea depends on whether the new product will meet your needs.
"Customer choosing a new 18 month contract would be entitled to one free house move and a wireless router. The 12 month contract option does not include a free house move or wireless router"
http://www.plus.net/support/service/policies/product_change_policy.shtml

[#5]

Based upon that it appears that changing product would be the sensible thing to do, especially as it seems there are no additional charges and where we're possibly moving to is also a Market 3 exchange.