Average price for an Uruga scroll on Teva is around 18s-20s in Eld from what I see on sale stores. Though Bijou might be different and I heard that stuff there cost more so I'm not sure.
Well, on Apoline I usually sell my Uruga Scrolls for around 17s... which is about the middle of the road when it comes to prices... the highest ive ever seen people selling Uruga scrolls for on Apoline was 23s... the lowest 15s... im sure prices dont vary that much between servers... so i would say 17s is a safe bet
I've seen vendors open with Uruga scrolls for 40s+, some as high as 50s, lol.
The standard price did seem to be roughly 20-25 for stores selling, with buying vendors offering 10-15. More often than not these days though, vendors are demanding 30s.