So let me get this straight, It's $39.99 for a complete Download and you don't have to own any DCS title? and if you do own BS, BS2, A-10 or FC2 it installs into one of those?
Yep...sort of... the download includes the new DCS common flight sim, called "DCS World". The P-51 addon installs as part of that, and the basic "World" sim comes with an SU-25T - nothing else yet. Apparently patches are forthcoming which will incorporate BS2 and A-10C if you have those already, but as of now they are still separate sims.
To back up Ruhroh, the P-51 is a great flyer
Possibly the best representation of a warbird in a PC sim yet.