Thats assuming someone has both 150 dex and 205 stamina with a bracelet slot open... both fairly unlikely on siege as it would require risking a lot of very valuable (much more valuable than this item) items to get those stats.
On this shard 99/100 (generously) 8 dex is going to beat 5 stamina on a bracelet, if that is the only difference between the two.
Don't wanna bash on the item, and its not BAD by any means, but I highly doubt its value would exceed that of an imbued bracelet with instead of 5 stamina 8 dex... which honestly could fetch a decent price if you just consider the ingredients required to cap HCI and DCI which is around 200-500k depending where you buy your ingredients. It's a solid item, but as Bo said, not blessable good, so that hurts the value.
Same ring but with 7 dex over stam and 13 HCI/DCI is pretty much the same thing, and hurts MUCH less when you invariably lose it.