Motion blur does not worry me. There is an algorithm that I'd like to try out, with refinements to suit astrophotography without tracking. I'd need to motorise at least one of alt/az axes to make it work. See:
Alex Rav-Acha and Shmuel Peleg (2005), Two motion-blurred images are better than one.
Pattern Recognition Letters, vol. 26(3), pp. 311-317.
Here is a preprint copy.
The "mirror flip" problem can probably be worked around by blocking the light for a few seconds before and after the shutter is opened. Cheap webcam is not an option at present, because it'd need a not so cheap laptop.
Paul, my scope is an 8" f5 dob.