Two things here: a) it gonna cost you more than 20k, at least couple hundreds. b) if your intention is to use it as a part of 5 piece set it's completely useless, the 12 player buff will only work for you, other members will see it as "health increased by 0" when you switch to a primary bar. There are actually a few threads here regarding this bug, but ZOS seem to do their best in ignoring this problem.
As is now, the best way to implement ebon set in a build is to use jewelry + chest + legs along with crafted Armor Master/Hist Bark/Tava's Favor for weapon, shield and other pieces.
The blue plates are nice, but the brown ones seem to last longer.
Do many nMOL pugged runs, ask in group if anyone got an Ebon Shield and offer to buy or trade for it. If you have an AD char, go to Rawl Ka, many players that hang out there do nMOL runs.