Not all dealers are offering the special. I have recently confirmed that it is still being offered by Gary at Off We Go Rocketry,
https://www.offwegorocketry.com. Apogee is not currently offering the special, see
https://www.apogeerockets.com/Rocket_Motors/Cesaroni_Propellant_Kits/Cesaroni_Certification_Special.
If you buy online and have it shipped, don't forget that, since an L1 case is only about $30, you don't really come out ahead because of hazmat shipping. You're better off buying from your local dealer, even if he is not offering the special. L2 cases are more expensive so you may come out ahead if you get, for example, a 38mm 6XL or a 54mm 3 grain. You can save a substantial sum if you are bold enough to do your L2 cert flight on a big K motor and get a free 54mm 5 or 6 grain case.