Le forum Basses n'est pas aussi vivant et animé qu'il le mérite !

il existe pour les guitares et basses " anciennes " une cote ( probablement basée sur des constatations de prix de vente moyen )

Here is the Blue Book info:

Mint $8,000
Exc.+ $6,500
Exc. $5,500
Avg.+ $4,750
Avg. $4,250
General $3,500

The Blue Book uses nine grades, with detailed explanations defining the different qualities:
100% New
98% Mint
95% Excellent Plus
90% Excellent
80% Very Good Plus
70% Very Good
60% Good
50% Fair
40% Poor

100% - New - New with all factory materials, including warranty card, owner’s manual, case, and other items that were originally included by the manufacturer. On currently manufactured instruments, the 100% value refers to an instrument not previously sold at retail. Even if a new instrument has been played only once and traded in a week later, it no longer qualifies at 100% - no dealer is going to buy the same guitar at the 100%/New price since they can buy it at the wholesale price. Likewise, no independent buyer would buy a used guitar when they could buy one brand new from the same dealer. The 100%/New condition factor only applies to guitars that are currently manufactured or that have been discontinued no later than 2007 since it may take a while for inventory to sell out. It is instinctive to consider the 100%/New condition factor a “mint” category, but the reality on vintage instruments is that if it is truly mint, it needs to be evaluated and appraised individually.

98% - Mint, 9.8 - Only very slightly used and/or played very little - may have minor “case” wear or very light dings on exterior finish only, without finish cracking, very close to new condition, also refers to a currently manufactured instrument that has previously sold at retail, even though it might be unplayed. On vintage and used instruments, this is as good as it can get. May have slight finish scratches - otherwise as new. Also, should have original case.

95% - Excellent+ (Exc.+), 9.5 - Very little observable finish wear and possible fine scratching, perhaps some light plating deterioration on metal parts, may have slight neck wear. No major dents, dings, or other problems.

90% - Excellent (Exc.), 9.0 - Light exterior finish wear with a few minor dings, no paint chips down to the wood, light oxidation on metal parts, normal nicks and scratches, light observable neck wear in most cases. No major problems or issues.

80% - Very Good+ (VG+), Above Average, approx. 8.0 - More exterior finish wear (20% of the original finish is gone) that may include minor chips that extend down to the wood, body wear, but nothing real serious, nice shape overall, with mostly honest player wear. Any repairs, alternations, or modifications should be listed separately on 80%-40% condition factors.

70% - Very Good (VG), Average, approx. 7.0 - More extensive and visible exterior finish wear/deterioration that could include some major gouges, nicks, and scratches, visible player arm wear, and/or fret deterioration. Sometimes, handling and stage wear (gouges and chipping around the outside of the body) contribute more to this condition factor than playing wear (neck, fretboard, frets, and top wear). Should include original case on recent mfg.

60% - Good (G), Sub-average, approx. 6.0 - Noticeable wear on most areas - normally this consists of some major belt buckle wear and finish deterioration, may include cracking, possible repairs, or alterations. When this condition factor is encountered, normally an instrument should have all logos intact, original pickups, minor headstock damage, and perhaps a few non-serious alterations, with or without original case.

50% - Fair (F), Below Average, approx. 5.0 - Finish and/or colors are still discernible, some parts possibly missing/replaced/ repaired, could be either refinished or repaired, structurally sound, though frequently encountered with non-factory alterations and other problems. Must be playable. This condition factor is not valued in the Blue Book of Electric Guitars.

40% - Poor (P), approx. 4.0 - Ending a life sentence of hard labor, must still be playable, most of the licks have left, family members should be notified immediately, normally not worthy unless the ad also mentions first year ‘Burst and original owner. May have to double as kindling if in a tight spot on a cold night. This condition factor is not valued in the Blue Book of Electric Guitars.

en bref, gardez vos pelles qui ne coutent quasiment rien à l'occaz en ce moment bien à l'abri et ressortez les d'ici 15 à 30 ans pour peut être faire une belle plus-value