I'm assuming you got that $20 fee from the web store? Unfortunately, that's just a result of a not-so-great shipping estimator that we use with our web store. It has a hard time doing a good estimate on the large range of stuff we sell, from a $20 EGT probe up to $10K in a huge, fully loaded SkyView system.
We don't have any handling charge, and never have. We do of course charge shipping. If you look on the manual printed form, for an EGT probe, that's $10 for UPS ground within the US. While that may sound high for a $20 item, that's just the reality of what box costs to ship via UPS these days.
Rest assured that if you called us, placed a fax order, or a web order, you would get charged the same for shipping. We adjust the web amount to be correct before we ship, but we know that may not have been obvious when placing your order.
We're not trying to drive customers away, but at our volumes, we're also not perfect at shipping small, low cost items. Sorry for the hassle.