I have a tentative LAS trip planned in the next couple months but really won't know if it will materialize until 48 hours before expected departure. A 'flex' ticket on DL in coach is $2400 r/t

I was wondering if there are any DL fare classes or ways to purchase that work like Southwest where you can turn even their cheapest ticket back into the dollars you spent to use towards a future flight as long as it occurs within 12 months? DL's non-refundable cheapest fare for the dates in question is currently about $410 vs Southwest at $447. Would rather fly DL but don't want to throw away money for no reason if I don't end up going. I couldn't find anything on their site about it other than checking 'refundable' on the search screen and seeing what it gives you, which resulted in the completely ridiculous fare.