This is a slight lowball in my opinion.
Yes, it's well within the salary of contemporaries (i.e. Karlsson, Doughty, Pietrangelo) but with the cap going up I'd expect Subban to look for 8x8. Ultimately I think they settle somewhere in the middle.
IF it's true and that's MB's first offer than that's not a lowball offer at all. Not for a first offer. That would actually be a very very fair first offer. It would show that they're not going to dick him around...unless they're very firm on 7x7 which would be silly.
If PK signed that it would be amazing only better if he signed it 7 per at 8 years. If we get him under 8 mill that would be really nice. I'm fine with anything under 9 really.
If 7x7 is really their first offer than I don't see negotiations taking too long.
A small but fervent part of me still wants PK to shock and sign for like 6 million per. If he hasn't been dicked around so much he probably would have. And I'm not even talking about the bridge deal. After PK agreed to that bridge deal the team should've treated him like gold.
Still, he could do it just to show that he's the classiest athlete ever (hell he's up there even now imo). Mind you the fact that he hasn't demanded a trade shows he's a rare breed of class.