Cancer doctor? Well if you are dealing with the big C, I send my sincere best wishes to you. I hate seeing people go through that.
Ensure doesn't bother me much, but yeah it is damned pricey. If I had to guess, it's because so many hospitals have it on the list of things to provide, and if any industry likes to overprice like mad, it's ANYTHING remotely to do with that industry. I swear to god, it's crazy.
A personal example from about 5 years ago :
I worked on some PCs that were being installed at a midsize hospital in Texas. Now these workstations didn't have any special hardware in them, they were semi-rebadged HPs (with a cover plate blocking the USB ports, glued on with a logo). They had XP Pro pre-loaded (this was just before Win7 launch, so at least they didn't have Vista). Other than that, all they did was run web-based apps to a hosted service for looking up info and entering appointments. They were Intel Pentium Ds with 2GB DDR2-667, 80GB Sata Drives, and no optical drives at all (which makes sense I guess). They had locks on the casing so they needed a maintenance key to replace/clean/upgrade if need be.
My job was to train a couple of people at the hospital in their use, and general troubleshooting, so that they could create some materials for bringing new hires up to speed as they came through. Anyway, I got to see the bill for these systems :
$3,800 each. The 17" 4:3 LCDs that came with them, another $400 each. Yep, $4,200 for a Pentium D and 17" LCD, complete with awesome 2GB ram and 80GB hard drive. No special software, no special hardware other than a glued-on plate to block the USB ports. The insane price didn't even include the service, that was a separate monthly charge of astronomical proportions. Perhaps the most insane thing about it was they didn't have a requirement to use any particular PC to access the site either, it was just 'recommended'. Hilarious.