He's been worth more than he was being paid then so giving him a four-year deal on £150K is just back pay IMO. How much were his two goals against Barca worth?
That's a lovely idea but for every Wijnaldum you'll have another player who's ended up being paid more than they were worth. I'm pretty sure when Ox renewed his contract he didn't tell the club to deduct £x from the new deal to cover the months he was out injured in the previous 2 seasons. Football is a business and just doesn't work like that.
Furthermore, he's been in on/off contract negotiations for the past 18 months - had an agreement been reached he'd have been earning more throughout that time, the reason why he hasn't is as much down to him as the club.
You say it like its a given he will suddenly nose dive just because he is over 30, We have taken Lallana off the books, Lovren etc that will of freed up some money, If Gini is still below 100k per week considering all he has done either give him the higher wage or sign him with some sort of bonus as he has more than earnt it.
This is all on the assumption wage is the problem, I'm not convinced it is, i think he does just want a different challenge. I think if that ends up being Barca he will regret it anyway, they need an over haul and Koeman maybe there not which would be a pull for him but doubt he will be there long
I didn't say he'll suddenly nose dive now he's 30 but how many players at 33-34 will be playing to the same level as they are when they're 30? Very very few I'd say, if any at all. Wijnaldum will not be as important to the side and playing as regularly as he is now in 2-3 years time, that's an absolute given. Paying Wijnaldum £150k over the next 2 years is fine, committing to paying him it for another 2 years after that is a huge gamble, a gamble the club won't want to take. I don't think they will but I hope a compromise is reached - something like a 3 year deal with an option of a 4th if he's played x amount of games in his 3 season.
I don't understand your point about Lallana and Lovren leaving - the club aren't going to pay x more just because they've saived money on y, they'll only pay it if they think they're getting value. And what we saved on them will barely cover Thiago's wages.