That obsessive hand washer would be me, Rachael. We go through about a bottle a week just in the bathroom so it was getting pricey.
This may seem silly to even write this because it is super simple but, to save money we bought a dial foaming handwash ($4, or you can buy a less expensive Bath and Body Works one for $1-$2 on sale), and a very large bottle of regular handsoap ($4). We then make our own foaming soap by putting a small amount (maybe 1/2 inch or so, or a few good squeezes from the big bottle of soap) of soap into the foam dispenser and filling the rest with water. That's all foam soap is anyways. So instead of spending $4/week (or even $1 for the cheaper non foaming soap) we spend mere cents each time we fill up the bottle.
That I can do. The one big bottle of hand soap has lasted us months and we still have quite a bit left. And the foaming bottle was a one time investment so basically we will just spend $4 every 6 months for hand soap in the bathroom.
Now I can wash my hands to my hearts content!