the subscription is intended to be what it says: a subscription with monthly 1, 3, 5 packages - the [BUY ALL] is just an additional option and makes most sense for the plus, because this library is only available online.
the SE subscription standard is identical to the SE DVD standard library, as everybody can assume a SE subscription extended should follow, which would be identical to the SE DVD extended library (both together, std+ext = full SE)
the plus package adds nice to both - the DVD and the download product in the same way.
for everyone intending to purchase the SE std in one run i would recommend the DVD, simply because it is cheaper, except you need it *instantly* and have a very good internet connection ...
and yes: subscriptions and other download products are only available in EUR currently - we all just can hope the USD returns to a *normal level* next year, though the signs don't look too good IMO ...
christian
edit: seems paul types much faster than me ;-)