Personally I'm not very interested in Dobson for the following reasons:
1) Because of his offensive season 2 years ago and because he plays RHD, the cost to acquire will be high.
2) Similar to above, but the cost to extend will also be high.
Generally speaking, the combo of spending a high amount of assets to acquire someone, and then signing them to their max contract is kind of the worst way to build your team. Not saying you should never do it, as it was a great move for the Panthers getting Tkachuk, but these moves are the costliest.
But the other big thing is, there is a reason why a very large percentage of Islander fans have been ok with moving Dobson for almost this entire year, and it has nothing to do with winning the first overall pick. They understand point #2 above, and have been watching his defensive play and it's not something they think they should spend 9 or 10 million on.
My fear would be you spend a ton of trade capital on him and then a huge amount of cap space (he'd be paid as our #1D until Morrissey gets re-signed), and then if his defense doesn't improve you can't trust him for big minutes in the playoffs and now you have a 10M Power Play specialist.
For me, the cost to acquire would have to be reasonable, and his contract demands would have to be reasonable based on his overall play, which doesn't sound like his ask. And then you have the additional issue with the Jets needing to re-sign Connor and Samberg, and if they can't sign Ehlers (and even if we can), we have a huge need to improve the top 6/9, and now we don't have the trade capital and certainly not the cap space to improve it. You'd likely need to include Demelo as well as you'll need to move him from a position perspective as well as a cap one. You don't include Salo because you'd need his ELC more than ever.