Cel paint can be restored. Paper restoration is trickier and more expensive, and if the cel material is damaged in the are to be covered by the mount, don't worry, but cracking of the actual cel on any of the character is not good. Give the piece a miss. Master, production, hand-prepared, colour laser, etc. Can be well worth the extra cost.
Some collectors only collect master ground set-ups.
After that, hand-painted and colour lasers don't add much monetary value, but they do look great and really can enhance the visual enjoyment of a piece. Sometimes if a piece can be directly attributed to a specific, sought after animator, the price may reflect that. - Signatures. A Walt Disney signature usually adds around 1500 to a piece. A studio signature, i.e. others authorized to sign for Walt, add about 100, and the Marc Davis, Frank and Ollies, should add about 35-50 for each signature. If a cartoon won an award, or was otherwise particularly significant as in the first introduction of a character, etc.