Well they as much as admitted that they merger of non-afterglow and after-glow was about as creating as little work as possible for the Dev team (creating one version of the weapon instead of two). Since they didn't want to put the extra work into coding afterglow for Ergons, then the only fair thing would be to reduce their upgrade costs. I think they should share the same cost as REMs with afterglows. After all SE established the value of the afterglow affect as 9999 plutons/beitsu/boulders. Since Ergons lack afterglow they should cost 1 rock to upgrade.

If we do see any adjustment, which is doubtful, it will likely be splitting the difference and allowing Ergons to upgrade for 5k.