I've been doing research about alternatives to asacol since asacol is very expensive.
A cheap alternative is sulfasalazine (azulfidine), but many have allergic reactions to this medication. It has sulfa in it. One person recommends the enteric form of this drug.
Lialda isn't cheap, but they have a patient assistance program for it right now.
Colazal may be an alternative, and there is a generic form called balsalazide disodium which will cost much less.
Other drugs that may be used to treat UC are:
olsalazine (dipentum), mesalamines (which is what asacol is), pentasa, apriso, rowasa, canasa (in Canada canasa is called Salofalk)
I've been gathering this info for a few days. I got it from the Internet so I would definitely consult your doctors about accuracy.
Also, some recommend buying Canadian Asacol. I might be going that route. One person recommended universaldrugstore.com Another recommended canadadrugs.com
Also, there is a thread titled "When is asacol going to go generic?" There is info in there about ordering Canadian.
God Bless :)