Hi ACI, I have in the past used a CPL directly on the lens, then a Cokin holder with ND grad on top of that. It is fiddley as you have to readjust the Cokin holder after the polariser. Vignetting is the big problem once you're doing any sort of Heath Robinson affair like this. As you have said, once you go up to Z Pro (Lee) size the CPL are the same cost as a cheap lens. I can get away without ND grads to some degree with PPing different exposures, but there is no alternative to the CPL. For me, I can see that I will get the Lee (or hi tech) set up at some point. At the moment I'm never very happy with CPL on uwa anyway so no hurry
Nex 5, Nex 6 (IR), A7M2, A99 and a bunch of lenses.