The price of the VGN is stable from around 8months. It is changing only a bit (between 8-11k/one VGN.
Also, I'm not a fan of any kind of taxes. Prices will just raise by x% and nothing else will be changed.
What if you decided to sell your SPs/Bet stuff w/e else. You must go a market place and just put a shop to wait for an offer for your item. No one is making 10 different speakers to sell all his things, that's a waste of time.
It gives: 12% dmg to devils (PvP) and 12% dmg to angels (PvP), 3% pvp damage, 5 ress (for example if its a water fairy, it gives water ress), 5 elemental Energy (same as with ress). Basicly this ress and elemental energies are useless.