What This Means
The best sailing is still strong on paper: Ovation of the Seas on a 7 Night Southbound Alaska & Hubbard Glacier Interior, departing Seward on 2026-08-28, with Cruise Fare For 1 Guest and $50. But that is the exception, not the rule. Most of the tier does not look like that.
What holds the tier back is depth. The average top-score profile trails the stronger mid-tiers, and the region mix is too concentrated to make the tier broadly useful. If you are looking for a practical entry point, 800 and especially 1200 are better places to start.
In short: 600 has a headline Alaska outlier, but not enough supporting inventory to make it the best value tier.