IE: indexOf results in "object doesn't support this property or method"
yeah, IE<9 doesn't support indexOf. You can implement a shim like the one showed here: https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/indexOf
Or if you already using jQuery you can use inArray. Also underscore has an implementation for it.
Simply changed to the use jQuery.inArray. Thanks to ZER0 for the heads up
if ($.inArray(dealWith, buyArray) != -1) {