I see there are terms for Used and New which I assume informs how the data is pulled from VGPC. But I'm trying to figure out how to describe whether a game is:

Loose
Loose + manual
With Box
Complete with Box
etc.

Anyone have any tips on how that's done here? Thanks

Yup, I believe the new/used terminology is used to select the right VGPC stuff.

If you want to select these other options they are available via Quick Add (or via Quick Edit if the game is already in your collection).
So once you select the button for new or used, a new selection of options should show up on the form. These are as follows:
Has box/case
Has cart/disc
Has manuals
Has extras

So basically with this stuff you can put a checkmark next to which components you have (case, disc, and manual) and from there specify the quality of each item (from mint to very bad). Also these options only pop up for games marked as physical first. Here's an image of the menu options: http://i.imgur.com/WrwppEz.jpg

As far as how the site associates your New/Used data vs VGPC's entries, I believe it's something to the effect of:

New = New
Used with everything checked off = Complete
Used with partially/unchecked fields = Loose

Feel free to correct me if I'm wrong here moho_00! I couldn't find the post where you explained how this worked so I went off my shoddy memory :P

You guys pretty much covered it, but I'll also point out that on the Overview page, you should see a little icon that has a popover to explain how the pricing integration works. I'd like to put this same icon on Collection page itself next to the Est. Value column header, but due to the way I'm processing column headers (and sorting), it's surprisingly not an easy change. I suppose I could put it up in the top bar where the actual est. value is displayed on the Collection page, that might be a good compromise (and maybe even better overall).

That's where I saw it! Haha, I spent entirely too long scouring the forums for a post with that info... :P

Oh man I feel like a dummy. I had no idea that clicking "Used" would bring out all these options. I should have just tried it I guess.

Wonder if there is some icon, like a plus sign maybe, that would let you know "Used" is actually expandable?

Either way, thanks for the help dudes!