Assakuru, you can refer to this link to the updates for Bounty Hunter: https://secure.runescape.com/m=news/c=W3l8-nhvH2k/bounty-hunter-rework-beta?oldschool=1
As for the ability to trade artifacts/prices, I believe its temporary as it says the bounty shop is temporarily unavailable for the beta. I would just wait to see what the beta unfolds. It is a beta after all, so there will be things that will effect current prices. You do bring up good points though for Jagex to look at.