I recently found myself working with making price updates work in two places on a configurable product page. The previous dev had set up some jquery to try and catch the price updates and apply them to the button. Due to the number of configurable options, this would break very easily.
After a little digging, I found that Magento instantiates an object with all price containers that are set by default. Based on this, I felt we just needed to add an additional price container to the initPrices method on Product.OptionsPrice. I did a little reading on the Magento way of doing this, including the following article, but my methods never would over-write the default.
In the end, I was able to use the addMethods option from prototypejs to get my additional container, plus the default containers loaded up.
Id be curious how other people might approach this problem.