Condition, originality and modifications
How cosmetic and functional condition, repairs, replaced parts and originality affect valuation.
Cosmetic condition affects price, but there is no universal table that works for every type of gear.
Minor wear consistent with age may have little effect on a working stage instrument, while the same mark can matter more on a recent product or an example aimed at collectors.
Assess surface scratches, dents, cracks, corrosion, missing parts, discolouration and structural damage separately. Photograph defects and, where possible, compare examples in similar condition.
Avoid automatic formulas such as "minus 10% for every scratch". The adjustment should reflect how much the issue changes desirability, risk and restoration cost.
When an item has a functional problem, do not simply subtract the price of the component you suspect has failed.
A buyer must account for diagnosis, labour, parts availability, transport to a technician and the risk that the issue is broader than expected. With discontinued or digital equipment, an unavailable replacement part can matter far more than its theoretical cost.
Describe the fault in verifiable terms: what works, what does not, when the issue appears and whether a professional diagnosis exists.
An item sold "for repair" often has a different market from a working example. Technical uncertainty is itself part of the depreciation.
Spending €300 on pickups, tuners or components does not mean the instrument is automatically worth €300 more.
An upgrade may be valued when it is reversible, professionally executed, documented and desirable to a broad range of buyers. It can reduce value when it permanently alters the item, reflects a very personal preference or removes original parts that are difficult to replace.
Compare the original model with genuinely similar modified examples. If the original parts are included, say so: reversibility often reduces the negative impact.
Upgrade value and upgrade cost are different things. The market pays for what buyers want, not necessarily for what the owner spent.
A professional repair does not automatically make an item "worse", but it must be evaluated in the right context.
On recent gear intended primarily for use, a correct replacement may have limited impact. On vintage, rare or collectible equipment, original parts, solder joints, transformers, speakers, finishes and components can matter much more.
Always document what was replaced, why and by whom if known. Keep invoices and original parts where available.
If originality cannot be verified, do not present it as certain. A reliable valuation distinguishes between what is documented, what is probable and what is merely claimed.