I think realistically there are only 3 bonafide starters available: Markstrom, Saros, and Ullmark. And even then, Saros might not end up being available, and Ullmark has a 16 team NTC, so he may be difficult to move.
Presumably Markstrom will be cheapest, but he also clearly is not a longer term solution at his age. He’s just the most realistic option.
I'm sure Merzlikins and Gibson are also available, but are probably too risky given the cap hit and term left on their contracts.
Markstrom makes the most sense, given his presumed availability and likely acquisition cost. Saros most likely stays with Nashville, I don't think they trade Askarov yet and Ullmark probably requires a good return and long-term extension. Not certain that he wants to leave Boston just yet either and with a 15-team no trade list he could easily work the list to make himself untradeable and walk himself to UFA next offseason. I don't know enough about his personal situation to know if he'd be open for a trade this offseason or not. Worse case, NJ case sign someone to split time with Allen - maybe go after a Stolarz, Brossoit or bring back Kahkonen. Not ideal and I think a Markstrom trade is much more likely, but would still be a massive improvement over what they had last season in goal.
I think the Devils feel that one of the young goalies in Schmid, Daws, Malek & Poulter will hit. Schmid and Daws have both had flashes at the NHL level, with Schmid having the highest peak thus far. He has a .921 SV% and 2.35 GAA across 9 playoff games - 6 of which he posted a .917 SV% or better and 3 of which he played poorly. He was also .922 / 2.62 the prior season across 18 regular season games. Small sample size overall and he most definitely took a step back last season, but he can split time with Daws this year in the AHL before both have to pass through waivers the following season. Malek just turned 22 and has played very well in Finland where he'll spend another season before likely coming over to the US. Poulter came out of nowhere this season and has been phenomenal between the AHL and ECHL. All 4 guys are between 22-24 years old, so one of them most likely at least slots in as a backup the '25-'26 season. Can't rely on Schmid or Daws to be part of a rotation next season, but it wouldn't be out of the realm for one of them to do well if called upon.