On Monday, November 9, 2015 at 11:10:02 AM UTC-5, wrote:
I've seen them for sale on eBay.

The problem with most of the ones you will find is that they are either empty, or so old that i wouldn't trust the rubber parts. The worst part is that you need to empty the bottle in order to replace the parts, and can't refill it!
If you decide to buy the $700 refill kit, let me know, and i'll send you the extra hardware for the bottles... i have 4 or 5 now.
Chris