When reserving an airline reservation with Spirit Airlines, travellers should be aware of the Spirit Airlines baggage policy limits and policies in advance. When booking a base fare flight with Spirit Airlines, you will receive one complimentary personal item. When booking an airline reservation, passengers must pay between $28 and $37, or $36 and $45 if they wait until check-in.
https://blog.aircomodo.com/spirit-airlines-baggage-policy/