Are you comfortable buying it strictly as-is, with the model and working condition unconfirmed? At US$15, this is a strong bargain against the comparable market: it sits well below the US$23 25th-percentile asking price and far below the US$65 median. Even if it turns out to be a basic HydraMini-style unit rather than a larger model, the entry price is excellent.
The appeal is practical rather than audiophile-grade: Altec’s small rugged speakers are valued for easy Bluetooth use, compact portability, carabiner mounting, and, on HydraMini variants, water resistance, floating construction, and roughly 12 hours of claimed playtime. The black-and-white finish and clip make it a useful bag, workshop, or outdoor speaker. Before paying, confirm that it powers on, charges, pairs reliably, and includes the carabiner; at US$15, modest cosmetic wear or a tired battery would not erase the deal, but a dead unit would.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.