I think we'd pay the money in a heartbeat if he'd shown an interest in joining us. It's a bit like when Mbappe was leaving Monaco - sure, we threw our hat in the ring but was it ever likely?
I'm just a bit wary of anyone approaching 30 really. I know i'll get the FM jokes thrown at me, but how many top tier CBs in recent years have maintained their form into their mid-30s? It can't be many. Rio, Vidic, Thiago Silva, Godin, Kompany...their injury problems all ramped up as they hit 30, and they all seemed to decline at around 31-32. I seem to remember Koulibaly struggling with injuries in the past too. He could be a massive success for us, who knows? But I just have a bad feeling he might be a bit of a van Persie signing. We'll get 1-2 good seasons out of him then he'll decline and we're stuck with this 100m defender on huge wages, and we'll need to replace him again anyway.
A van Persie-esque catalyst signing is all well and good when he's the final piece of the jigsaw like RVP was in 2012, and you just need one big player to lead your team to success that season. But I don't think we're at that point yet. It's a big gamble is all I'm saying.