I guess the question I would ask is whether the OP was on board with the signing Moore. Sure, he played last year, but if you read his story about backing out, it sounded like he really hadn't done anything to prepare for the possibility of playing this year and ultimately didn't have his heart in playing.
He was going to cost us $2 million, so even if Waters costs us maybe an extra million it's not really a big deal if you were on board with signing Moore.
Waters played at a high level the last time he stepped on the field, and voluntarily didn't play a year ago because he wanted to be closer to home. The Pats tried offering him more money and he simply said no. I feel he is more committed to playing again but simply under his terms...in this case where he plays. I have no problem with that. And as many people have said, a year off may be good for him, might allow some of those nagging injuries time to have healed.
I would prefer that he come in next week, practice with the team for a few weeks so we can see what he looks like. If he isn't where we need him to be, then he can be cut before the opener and only any guaranteed money will count. They can hedge their bet by not giving him a signing bonus, instead guaranteeing his contract if he is on the week one roster or something like that.
There aren't going to be many upgrades, if any, when guys start getting released, and if there are, they likely are going to cost similar money. An upgrade isn't coming in at vet minimum money.