[Dave LaRonde] “But there are some pretty inexpensive video cameras that might do the time-lapse trick, too. I think a Canon XL2 might. Check out the Panasonic HVX200, too”
The cheapy camcorders can’t do single-frame time-lapse (rather, they record a “few seconds of tape” at a time) and they don’t have much adjustment of the length of time between “exposures.”
Using a digital still camera with software to trigger it, is the least expensive way to go.
The new Sony XDCAM PMW EX 1 HD Camcorder does offer single-frame time-lapse ($6,700 price-tag for the camera, when available.)
There is also computer software that will record single-frame time-lapse directly to the computer from the FireWire of any video camcorder.
Here’s a link for one such (Mac) product:
https://www.bensoftware.com/
Do a Google search for more info.