Price Check: Eternal Bow

Can someone help with prices for these 2 eternal bows? Thanks

1) 15^50
+30 health
req: 9
Crippling String

And, if you could, how much more would the same bow be worth with a 20/20 string instead?

2) 15%/-10 attacking
Enchantments last 19% longer
Ebon String
req: 12

never attach a weapon upgrade, as the increase in the price is minimal compared to what u can get out of the upgrade itself. that said, is the eternal bow from nightfall or before?

Thanks for the reply, both bows are from Prophecies, non-incriptionable.

up

Can someone help me with this?