Amazon offers Prime members the Bullet Bags by Protec Padded Gig Bag for Electric Guitars for $5.71 with free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $5.89.) That's $4 under the lowest total price we could find for a comparable gig bag. It features a sheet music pocket, backpack straps, and puncture-resistant headstock and bridge patches.

It's also available for Electric Bass Guitar for $6.35 $6.31. Again, Prime members bag free shipping. That's $7 under the lowest price we could find for a similar bag elsewhere. It has the same features as the above item.