Lets go over those avenues.
I am well aware of radshare, but its very unlikely to find a group of 4 people for a vaulted relic that has been gone for well over a year unless purchased. It can be troublesome to even find people for even non-vaulted relics. The system itself is still horrible, I've done plenty of radshares for AXI H6 for Hildryns BP and out of 5 different runs across a few days I never once received the BP. 20 total relics, and not one of them yielded a blueprint. Radshare isn't the cure all for bad RNG.
As for the market, at this current time people (including you I'm sure) are selling boltor parts/relics for extraordinarily high prices. So if you want to drop several hundred plat on a single piece/relic then by all means do so.
And finally as for Varzia, that is where I got the relics from to begin with. So frankly I'm sorry out of the dozen or so that I bought not a single one gave me what I was after.