What topology should I use if I'm wanting to obtain CC/CV -- 300ma / 180Vdc from a 120Vac input, where mains isolation isn't a concern? My application will tolerate slight overcurrent (maybe to 600ma) at lower voltages (90vdc), and will tolerate slight overvoltage (to 200v) if the current tapers below 300ma once exceeding 180V.
I'm hoping it can be as simple as a ballasted voltage doubler or something along those lines. The BOM for a single piece would ideally be below $20. I do not care at all about efficiency, only low BOM cost and "relative" robustness.