It has been forever since I've last played, and I can't seem to find info on these items anywhere any more -- were they discontinued, and if so, why?

It's unlikely I'll part with them unless a hardcore collector comes along; for the most part it's just curiosity's sake. I don't expect an exact figure, but any guideline amount would be lovely, thank you!

= + Aemis is 50m on the SS and Balrog is 50m in the MC (40m I believe, during fall)

= + Riptide is 95m on the SS

= + Eternal is 40m in the MC

I wouldn't expect the combos to go for much more than the total price of the pieces they're made from (90-100m, 135-145m, and 90m respectively). I don't think the legendaries are really popular anymore except maybe to collectors, but tbh I don't know much about weapons in general

They're only valuable for collecting purposes. For battling, no one uses them. So you'll have to appeal to non-battlers.