They take in the $1.375 M cap space. In terms of how much actual dollars the Sharks pay, I don't know. That's some complicated math based on how much of the season is left and how much is actually been already paid and stuff that we actually don't need to really care about.
So to sum it up. This is the breakdown.
Leafs take $1.375M of cap space and get Folino and the Sharks player in the AHL
Sharks take $1.375M of cap space and get the Leafs 4th round pick in 2021
Blue Jackets keep the $2.75M remaining cap space and get the 1st round pick and the 4th round pick in 2022.
Edit: Oh my goodness, there are some talks about trading Jeff Carter to the Penguins?? Per Bob McKenzie below. We all love Carter for what he's done in LA and all, but he's sorta never been the same since he had a big injury in late 2017 that nerfed his speed (age doesn't help as well). If this is true, I don't even mind it if the Kings retain salary. He only has one year left on his deal after this season (which only pays $2 million in salary). Also, it does give one of their prospects to crack the main roster and try to give some life to this team.
https://twitter.com/TSNBobMcKenzie/status/1381434937237180419Edit x 2: I love the trade deadline. This is the part where GMs just drinks a magic bleach and throws caution to the wind and make these trades and hope they hit gold and we laugh at them if they wiffed hard on it.
Taylor Hall is going to the Bruins, per Elliotte Friedman.
Edit x 3: Now, it's official. Per the Kings' Twitter. For a conditional 3rd-round pick in 2022 & a conditional 4th-round pick in 2023, Carter is going to the Penguins. Kings retain 50% of the cap hit which is around $2.6M.
https://twitter.com/LAKings/status/1381482252362788870