Check the booking class to make see if you will earn Skymiles, medallion bonus miles, and MQMs. The cheapest fares (such as V, which is often the lowest) do not.
http://skymilesoffers.delta.com/airline_partners.php#KL

Depending on how much value you place on the miles, it may be worth buying up to the DL-coded ticket, or to a more expensive KL ticket.