With the exception of real estate, cars, or other suitable large value purchases, if you can't afford to buy it in cash you really can't afford it period. Interest free with no hidden fees/penalties/gotchas is about the only exception, but barely.
Should be just like you treat a credit card... if you can't afford to pay the credit card bill off all at once for a purchase then you could never really afford that purchase.
I completely understand everyone has a different financial situation, but "financing" small purchases just sets up a mindset of overpaying or generating unnecessary debt. You're way better off putting the money in a savings account until you have enough to pay for whatever it is in cash.