An accessory has value when it reduces a larger expected cost or materially improves daily use. Price alone does not establish either.
Use an avoided-cost test
| Purchase | Potential value question |
|---|---|
| Case | Does it materially reduce the chance or severity of an expensive drop? |
| Screen protector | Is scratch exposure high enough to justify replacements? |
| Quality charger | Will it safely serve several devices and ownership cycles? |
| Power bank | Does it solve frequent lack of power rather than occasional anxiety? |
| Specialist mount | Does it improve safe use in a real routine? |
Illustrative comparison
A £28 case used for three years costs about 78p a month. A £65 premium case replaced after one year costs far more without necessarily providing proportionally greater protection. These figures are illustrative.
Include inconvenience and compatibility
A cheaper cable that charges slowly, cannot carry required data or fails during travel can have poor practical value. Conversely, paying for maximum specification is wasteful when the phone cannot use it.
Resale value is secondary
Accessories can help preserve condition, but rarely recover their full cost at resale. Buy them for protection and use, not as an investment.
Use a break-even question
If a case costs £35 and is expected to reduce the chance or severity of a £250 repair, the purchase may be rational even though no saving is guaranteed. If a cosmetic accessory costs £70 and offers no identified functional benefit, it belongs in discretionary spending.
Value the seller and warranty
Two visually identical products can have different value when one has a traceable supplier, accurate specification and workable remedy. The cheapest listing is not the cheapest outcome if failure leaves no recourse.
Related guides
- Accessory Costs Over Time
- How Much to Spend
Sources and editorial method
Information checked 26 July 2026. The comparisons in this guide are editorial methods, not current market averages or guaranteed valuations. Recheck seller, platform and provider terms before acting.
