I have been using Rectogesic for 12 years now here in Australia (that was 11 years with sucess and the last year not so much sucess so resorted to surgery last week).
Anyway I cannot believe you only just got it in the US so recently. The Rectogesic they sell here in Australia has 0.2% glyceril trinitrate. It costs between AUD $30 to $40 and with the Australian dollar on a par with the US dollar lately that means it's about US$30-US$40.
While it is not a prescribed medication in Australia it is a pharmacy only medication so you either have to buy it in person (yes I know Australia is a long way away but maybe a good excuse for a holiday?!) or you can buy online and then you just have to follow up with a phone call when you place your order.
The following online pharmacy was AUD30.99:
http://www.chemistwarehouse.com.au/product.asp?id=7376&Rectogesic%20Ointment%2030gThis second online chemist was slightly cheaper at AUD29.05:
http://search.yourchemistshop.com.au/search?w=rectogesic&asug=This one also had a phone number for international customers so it looks like they will ship overseas:
+61 02 8347 8188 (International Customers)