How is the European Visa Waiver program related to Spirit Airlines? Don't you just fill out this form online prior to travel and that's all?
https://esta.cbp.dhs.gov/esta/esta....C3D3C9A_kB78AC067-F363-E140-F70C-51FE803DFEAA
Tell us more about the .01 fare....
At that price, you can afford to be sent back
Spirit often has these deals. Price is one way on select days based on round trip purchase plus tax ($174 approx.). They do $9 fares often with the same conditions.