Cheap/expensive is relative. More importantly, insulin is only a tiny cost of the care of Type 1 diabetes. Diabetics need to check blood sugar levels anywhere from 3-5 times a day, sometimes more if ill or for other circumstances. Test strips can cost a patient as much as $1 per strip.

Also, insulin requires a subcutaneous injection for delivery. That means a new syringe 3-4 times per day depending on the therapy. Or, you could get an insulin pump at about $5k and pay for insets, tubing, reservoirs and other miscellaneous supplies. Those need to be swapped out every three days.

Want to add continuous glucose monitoring to your therapy? Even more supplies. Add it all up and treating T1 diabetes is nothing close to cheap no matter how deep your pockets are.

Insulin is cheap but diabetes is enormously expensive. Nytimes has an excellent series of articles http://query.nytimes.com/gst/fullpage.html?res=9907e2da1f30f...

The articles describe diabetes patients as floating "shipwrecks": a rudder broken here, a sail there, no one at the helm. It's a good analogy because, when you have diabetes, almost anything can fail without warning.

There's a whole sub-industry based on diabetes! You have goods providers shuttling out boatloads of sharps, insulin testers, strips, etc. A lot of companies profit beyond just insulin, which isn't terribly expensive unless you have to use a high dosage.