Walmart offers the Luv I111 Splitter Adapter with Dual Volume Control for $5.96. (Amazon offers it for the same price for Prime members; note that this item may take one to three weeks to ship.) Opt for Site-to-Store pickup to avoid the $4.97 shipping charge. That's the lowest total price we could find by $3. This device allows two users to share an audio device with a 3.5mm plug.