I think he's more than a bit behind Palmer though. I can't see the point in playing an inferior keeper for that reason. He's currently got 2 years left. At end of upcoming season he has 1 year left.
If it's a good offer he's got to go.
I'd agree with that, plus if you make him number 1 before he's ready there's a chance of damaging the lads confidence and him never fulfilling his promise.
As regards fee, I think we all need to be a bit realistic. Yes, Newcastle have a lot of money, but they still need to work within the constraints of FFP. They're probably looking at Griffiths as a low cost, long term option and they will know we need the money. Plus, can you actually say his displays last season for us were those of a £20-30 million goalkeeper? No, he's behind Palmer for a reason. If he could fetch that fee he'd be number 1 outright.
I think if we can get £3-4 million, plus add-ons, then it's a good deal. Not guaranteed he'll ever reach his potential. Look at Freddie Woodman, a former Toon keeper.