Amazon offers the Portland Design Works Shiny Object CO2 Tire Inflator with 16g Cartridge for $16.77 with free shipping. (Non-members can spend $35 to qualify for free shipping; otherwise, it adds $5.03.) That's the lowest total price we could find by $8, outside of 3rd-party Amazon sellers. This emergency tire inflator is compatible with Presta and Shrader vales and features a control knob, leather cartridge sleeve, and alloy construction.
Note that this item is out of stock, but can be ordered at this price for delivery when available.