Maybe the vet was talking about a different pill?  Tapazole is a relatively
cheap medication.  I take it myself, as did one of my cats for a while.  I
can't give you the cost per pill (say, a 5mg one) because my prescription
co-pay is $3.00 per vial of 30 tabs for its generic, which is methimazole.
However, when I was buying Tapazole from the vet (the cat was diagnosed as
being hyperthyroid & took it before I was diagnosed), it was not an
expensive drug.

Cathy

--
"Staccato signals of constant information..."
("The Boy in the Bubble")  Paul Simon

I was just talking with my friend about this, the one whose cat was just
diagnosed with hyperthyroidism. Tapazole is not expensive, as Cathy mentioned.
My friend's vet told her it only gets expensive if the cat lives a long time,
because she will have to be on the pills the rest of her life. However, if you
were to add in the necessary monitoring and blood tests to check thyroid
levels, I suppose it can add up.

However, I think I found what your vet was referring to:
http://www.radiocat.com/section5.html
That $800 is a figure given by the makers of Radiocat, who naturally want you
to use their radioidine product rather than choose pills.

I also found this which you might find interesting, although it's also written
by a clinic that specializes in radiation treatment:
http://www.felinehtc.com/faq.htm
What caught my eye is that he says that "Severe heart disease secondary to
hyperthyroidism can occur even prior to weight loss. Hyperthyroid cats' heart
rates are often between 220 - 350 beats per minute."
Not to alarm you, of course, since it seems to me her test would not have been
just borderline if she had a severe case.