Some of these sheets aren't necessary, I will probably have your inventory in an excel sheet. However, it can be fun for some to use sheets like these. I also found a cute character sheet.

What's generally important is to know the name, description, weight and average price if new for each item in your possession, my list will at least have the name, weight and average new value.

One last thing to note, as the player's handbook states, if you recover equipment or items or even if you want to sell back items, if they are in new condition and you have no standing or relationship with an average vendor, they will buy back at 50% for pristine condition, 25% for good, and won't want items in fair or worse condition. Fair condition can be restored to good for a fee by the appropriate service (tailor or blacksmith) I'm assuming it is a fee percentage of the value of the item. So items in damaged condition are as good as dead weight or carried as scrap or material for a proper armor set/weapon which will have to be made by the appropriate service for a fee likely greater than buying standard equipment new. Equipment and armor in patched or repaired condition even if not "good" will still be as useable as new, metal is metal, leather is leather.

It also says gems and jewelry are as good as coins for trade even if not in perfect condition. So the appraised value would stand for buying or selling without a markup or loss. Old dirty and scratched coins are as good a new ones and so fourth. There would still be a small percentage difference based on standing to convert from gems and jewelry to coins, but the armorer would take the appraised value of a gem or ring as payment at 100% equivalent to coin.

I hope my barrage of information isn't too much for any of you. I find this as enjoyable as playing myself.