* Plusnet Value: If you live in a low cost area it costs £6.49 a month. If you live outside one of these areas it costs £6.49 a month for the first three months, then £10.79 or £12.99 a month depending on where you live. See how we compare on price in your area.That implies to me that M2 pricing is intermediate between M1 and M3, but don't see that specifically stated anywhere.
** Plusnet Extra: If you live in a low cost area it costs £11.49 a month. If you live outside one of these areas it costs £11.49 a month for the first three months, then £15.79 or £17.99 a month depending on where you live. See how we compare on price in your area.
In fact, the contrary is true, where in this table M2 and M3 are definitely the same price. The table is clearly out of date in one respect at least, as Pro is shown as a fixed price, not a £5 boost.
Then we have the Fibre boost which says "Plusnet Fibre costs from £10 extra per month for existing Plusnet Value or Extra customers", (my strikeout as the wording with it is confusing when taken out of context like this), which may imply a difference depending on Market.
Then there is this page.
I think the new website and price structure is much better than the previous, but does rather restrict people to only being able to check their own area. But while drafting this it occurred to me that perhaps some of the above comes about because of the "Price Beat" promise, which I assume depends on exactly which LLU providers are available, independent of Market classification.