Walmart offers the Panasonic ErgoFit In-Ear Headphones in Blue, model no. RPHJE125A, for $7.59. Opt for in-store pickup to avoid the $4.97 shipping fee. That's the lowest price we could find by $2. These in-ear headphones feature a frequency range of 10Hz to 24kHz.
Of note, they're also available in Black, Orange, or Violet from $8.07.