I just saw the following note from Graalx2 on the live boards saying the following:

“We have found the issue with all of the legacies costs not decreasing as the legacy tiers up. It will be fixed in the next major patch (not tomorrow’s). There was a problem with rounding off that caused the numbers not to change as they should. This will correct all legacy costs for all classes.”

So, tomorrow’s patch won’t fix all the legacy issues 🙁  I’m going to hold onto my legacy upgrade scrolls till they get this all fixed, but I’d imagine things would be applied retroactively if you tiered an item up via the normal upgrade process.  I am pretty happy though that they did finally find and fix the problem!