Yes, sticker shock is a definite reaction when discussing solar imaging. The Daystar Quark is the cheapest approach, as far as I can understand, if you want to image in H-a (and it's quite fiddly, with complaints about QC variations from users).
Up to a 102mm refractor you can avoid the costly ERF filter and use only a UV/IR rejection filter in front of the Quark, as far as I understand the situation.
Also, you will get a deep red view, you will need a monochrome camera in order to be able to discern stuff (and colorize later the B&W image).
You can emulate a coronagraph with the help of an image processing tool (you overexpose the Sun disk, in order to get the prominences, then you remove automagically the white-washed parts of the disk)
N.F.