The unexpanded Vic-20 had 5K of RAM. This was quite small even by 1981 standards, but it was trying to be cheap enough for consumers to buy, and it succeeded, selling over 2 million units.
One reason for that figure was that it used static RAM chips, which are much more expensive per kilobyte than the dynamic variety. The documented historical reason for this choice is that Commodore happened to have a lot of spare 4kbit (0.5K) static RAM chips lying around at the time, and the engineers were told to find a use for them.
Was there also any cost advantage? Static RAM in principle makes system engineering simpler, because of the lack of need for refresh. Did that have any side benefits in terms of manufacturing cost? Or is it more like 'sure, dynamic RAM means you have to spend X cycles per frame refreshing, but other than that, there is no manufacturing cost difference except for that in the chips themselves'?
As clarified in comments, while the previous question about the memory configuration of this machine talked about cost and availability of the RAM chips themselves, this one is asking whether the use of dynamic RAM requires any extra hardware, apart from the DRAM chips.