The Iron Cross Edition has 8 Planes methinks and the light even less.
If you download the "free" game, with the 2 flyables, and buy cheap planes in these days or bundles, I think you are cheaper off, than ICE or LE and then adding content.
But if you want to support the developers, buy first the LE, than ICE and finally add all the content one by one anti-cyclic in the high-price days, just as I did....
PS: If you just want to play around a bit and have to watch your spendings, go for the free game and add the plane you want to fly in the offline campaign. There you should get along with maybe 8 planes from one side. I fell in love with the Pfalz III, I don´t know why, but that`s the way it goes. If you like one plane, you find that totally sufficient, if you do have limited spare time anyhow...