We don't need to make him a first choice CB though, do we, as long as we keep upgrading our squad Dunk may turn into a useful squad player, a reliable experienced option you can count on during a long campaign. Now if it was 2005 and we had prime Terry, Carvalho and Gallas competing for one of the two CB spots, the idea of going after someone like Dunk would have been odd, he'd have never had a shot in hell of getting on the pitch. But who in our current roster is realistically better than him based on this past season's performances? I'd say he was comfortably better than each and all of them.
Regarding the fee, I agree, way too much given post-Covid financial environment, Dunk's age and no resale value, but who knows what's really going on, how much Brighton demands for him or whether we even made an inquiry in the first place, it's all guesswork based mostly on self-proclaimed Twiiter ITKs and journos pretending to know something others don't.