My apologies if this has been brought up before but upon searching I only found this outdated topic by our friendly neighborhood BDW Admin and forum moderator El. (Here)
But, this becomes slightly more relevant with the addition of 2 new/newer resistance draining side weapons into the game (Basalt Dissolver and Blizzard Dissolver)…
If you ever get these resistance draining side weapons (the ones that go from E-M) you can actually upgrade them to max Epic for less boost power than other items. You actually save 14280 boost power, which can be useful if you have a lot of duplicates of this item, or no use for the item in general and don’t mind upgrading them to Legendary 1/40 to be fused away.
I imagine this was a conscious decision by Tactisoft to make these items more easily upgradeable and thus more viable and used in the arena to help balance their increase in resistance through the release of things like the arena shop and, more recently, new torsos.
Hope this helps, or you at least found this interesting. And if you already knew this, that’s cool too! Take care.