1) Delta has a "buy miles" special right now:

Buy Miles for You

Need a few more miles to earn Award Travel or upgrades? Looking to increase your account balance? For less than $30 USD, you can begin to open an entire world of travel opportunities. See our Limited-time offer for the holidays.

You can purchase up to 30,000 miles per calendar year in increments of 1,000.
Purchased miles are applicable toward all SkyMiles awards.
The cost is $0.0275 USD per mile plus a 7.5% Federal Excise Tax. An additional 6% Goods and Services Tax (GST) applies to purchases by Canadian residents.
We accept American Express, Visa, MasterCard, Discover, and Diners Club.
Check your mileage balance to find out how many miles you need prior to making your purchase.



Terms & Conditions
Purchased miles are nonrefundable, and should post to the appropriate SkyMiles account within 48 hours. You must be a SkyMiles member to purchase miles. If you aren't a member yet, you can enroll now. Purchased miles do not count toward Medallion® or Million Miler status. Prices and rules are subject to change without notice. Taxes and fees for Award Travel are the responsibility of the passenger and must be paid at the time the ticket is booked. Award Travel seats are limited and may not be available on all flights or in all markets. All SkyMiles program rules apply. To review the rules, see Membership Guide & Program Rules. Offers void where prohibited by law. Additional restrictions may apply.

So, for $29.56 you can buy 1,000 and get a 20% bonus of 200 miles. Use those later.

2) If you have a friend or family Medallion member, they can transfer 1,000 miles to your account for $35.00 but no bonus miles

3) If you have a credit card like American Express, you can transfer 1,000 or so points to Delta. American Express posts within a couple hours.

Good luck!! Travel safe