Thanks mb504,
This looks to be the all round best deal, this way I can still use all of the original set tools and still upgrade to the LiOn 20 V batteries.
Granted, over time this will burn out the tools (more voltage and amperage) but by that time hopefully they will have perfected the battery size portable hydrogen fuel cell tools.
https://www.toolbarn.com/dewalt-dca2203c.html/