Selling back equipment

[Sextus Orange]

It seems like I've seen somewhere that you can sell back equipment for full price if it hasn't been used in a certain number of battles or at all. If this is true then what's the battle limit and are there any items it doesn't apply to?

[Zansatsu]

I think the limit is five battles, though I may be mistaken.  There aren't any items that the rule doesn't apply to.

[Sensurugi Tenshigo]

Zan is correct on the number of battles, however you cannot sell back coatings or organoids.