Car Dollies Needed....Make or Buy??

I have three sets of the black HF version, they work okay for what they are. It does usually take two people to move a complete car, but I have a small winch that makes it a one person job. Very useful for moving a car sideways, into a confined space.
I also have a pair of the cheaper diamond plate version from HF. Don't bother, they're garbage.
If you have a floor jack (have three HF Jack's, very good for the price!) there is no need to have a jack on the dollies. Save yourself some money.