Needles & Grooves

How does one do that?

Buy a gift card here and email it to yourself. Return to the main gift card page where you'll find a link to Redeem a gift card on the upper right. Copy the code from your email and pop it into your account, and shop away! Bandcamp Gift Cards

Why would one do this instead of the regular checkout?

@wokeupnew Bandcamp treats each artist/label in bulk orders as separate transactions. If you order from a bunch at once, it could trigger your bank/credit union to suspect fraudulent activity and deny the transaction altogether. Having gift credit on your account consolidates those many transactions into one, so you don't get flagged for a fraud call.