I travel solo often. Is the $80 worth it to you? Will you add an extra day to your tickets? If you're taking DME you'll leave the resort around 2:30 so you don't get a full day in the park. Might not be an issue. On my Sept 2017 trip I had a 6:30PM flight out and spent departure day in Disney Springs and taking buses to different resorts. Made a whole day out of it. But the later flight was less expensive for me than the early flight so rather than take the more expensive flight I chose to save money. I also fly across country so I like getting into Los Angeles late - much less traffic heading home.
Is this a first solo trip for you?