Viabtc used to have a market place for hash. I thought they still did. Although it probably caused issues when they were trying to refund people as they'd have paid about 3x what viabtc offered, do they not still have that function? Are you signed in to the cloudmining bit?
I wasn't signed in to the cloudmining part of the site, might be why I can't access it. Trying with the sign-in this time.
Edit: Signed in, still can't see anything in regards to cloudmining. I bet they shut down all of their contracts a while back and stopped offering cloudmining contracts, I saw a tweet with an announcement about their hash marketplace from 2017
here (click to view), but that also gives me a 502 even while signed in to the viabtc site.