Where do you buy your vinyl?

Best used record store in the universe: Jerry's in Pittsburgh.

By all means, search out a local Record Store and support small business.  Most if not all used record stores can also order you new releases from just about any label.  On the occasion that I buy online, I buy direct from the independent labels KScope and InsideOut Records.

When you talk about “great” vs “ok” recordings, are you referring to the same title released at different times by different labels?  For instance, the original release vs one’s done later by Classic Records, etc?

Or are you talking the same musical piece performed by different orchestras on different labels (this mostly in the classical genre)?

Regarding "best copies". You need to read the forums and familiarize yourself with writing styles that gel with your connection to music. Then seek out the recommended copy 

@jeffrph Thank you for the suggestion. Love that he play grades and includes the country of origin/version!