Bicycle Austin forum

Having just bought a second-hand folding Batribike for my bicycle-unfriendly Mrs to use, I have been considering getting one for myself so we can both use them when away in the camper.
I have been shocked at prices of 'decent' battery powered bikes from good names like Trek, Specialized, Cube etc.
I love my 8 yo Rockhopper which I've upgraded extensively and as its so fast, comfy and good handling I'm considering getting a kit to convert to battery power.
Has anyone on here done a conversion and could recommend a suitable self-build set up? Or should I just fork out for a decent ready built job of which there seem to be a plethora. And what can you say about electric skateboards? I'm looking for a one for my son, found some good here, but can't choose.