Ultimately, selling and buying used skydiving gear is more of an art than a science. Experienced skydivers often rely on:
Safety always first: Remember, skydiving equipment directly impacts your safety. Never prioritize price over thorough inspection and verification by qualified professionals before buying or using used gear.
Remember: Skydiving is a sport with inherent risks. Prioritize safety and responsible decisions over relying on an oversimplified "calculator" approach when dealing with used gear.
Exercise your judgement before buying used gear. Here are some other factors to consider for main canopy:
Reserve canopy
Automatic Activation Device (AADs)