If you are creditworthy and can charge $6,000 within the first six months, consider applying for the Amex Platinum card (NOT the Delta Platinum Amex card). The sign-up bonus is at least 100,000 Membership Rewards points (and maybe more if you get a targeted offer at cardmatch.com), which more than offsets the $695 annual fee. The card gives you access to Delta and Priority Pass lounges, and Amex Centurion lounges, too. (The LAX Centurion lounge is currently closed, but you'd probably prefer to use the DL lounge so that you don't have to leave the DL terminal.)

After one year, close the Platinum card, unless you think that you can get enough value from the card to justify the $695 renewal fee.