I just priced some things and I'm surprised at the low rates and the number of hotel options available. Anyway, I priced everything a la carte and as a package on Expedia.
Air via Spirit website: $306.76
Car via Dollar website: $117.61
Fairfield Inn Marriott Village via Marriott website: $351.00
Total a la carte: $775.37
Same components via Expedia.com as a package: $757.52
Personally, I wouldn't go with Expedia just to save $17.85. I'd rather be able to directly contact Spirit, Dollar, or Marriott in the event of a problem. If you book with Expedia, you'll need to use their Customer Service if you encounter a problem before your trip.
Also, if you've never flown on Spirit, make sure you understand the drawbacks. Aside from the fees, make sure you know that you'll have limited options if your Spirit flights are canceled. Spirit is much, much smaller than Southwest, America, Delta, or United. If a plane breaks or a crew member calls in sick, they have fewer resources available to recover. If you flight is canceled, they usually only offer to put you on the next available flight (which may be days away) or refund your money. If you take the refund, you'd be stuck buying a last-minute ticket on another airline.
For more details, check out this thread from the Transportation forum:
https://www.disboards.com/threads/how-bad-is-spirit-airlines.3664741/