So I just bought one of these capes for a whopping 1.9k tokens and I came to the conclusion they are inferior to a skillcape. There is literally no benefit to use these capes over a skillcape (except for the +1 bonus is all attack styles, but this is pretty much neglectable), making it dead content once a player has mastered a skill. (which isn't very difficult to achieve)
I therefore suggest to either change the stats of the capes, or lower their prices.
The stat changes should make it an unique cape which benefits the player in certain situations, whilst not making skillcapes useless. My suggestion is to give it a significant enough prayer bonus to use it instead of a skillcape when prayer is a deciding factor. Skillcapes give a +6 prayer bonus, so a +8 or higher bonus should do the job. (in the old version of runescape these capes had a +12 prayer bonus) In addition to the prayer bonus they could also give a small defense bonus in all styles, however I think this might make it a little bit too strong.
My second suggestion is to lower the price significantly to make it a cape low level players can buy with little effort. It will then serve as a better version of the legends cape/obsidian cape which are very easy to get. A price of 500ish tokens should make it harder to achieve than one of the previously mentioned capes, but still easy enough to make it a desirable item.
I personally am a big fan of my first suggestion, but the second one will also be a nice change.
Thank you for reading.
