Just started playing again. Need help about gear, etc

Started playing again and I don't know what stuff is still valuable and what should just be destroyed.
I have a couple of Arbiter sets, accessories and weapons with "common" remodels plus some other random stuff as well. Most of these weapons even have those expensive shop godstones that cost around 1k credits before but I don't know if these are still worth anything

Can someone please help? And how do I enchant/socket manastones without failing? It always seems to fail after I get it to +5

Thanks in advance.