I doubt I'll get to the point of worrying about standardized pricing for shipping soap, but I do manage quite a bit of shipping of small nursery stock where I work. We do UPS and Priority Mail for the most part.
One big thing to keep in mind with UPS is that they currently update their pricing because of fuel costs almost daily. I do have to give them credit, I've seen their rates drop a couple of times, but obviously not as often as it goes up. If you ship regularly (it doesn't have to be huge numbers, but, say, several boxes a month) you should seriously consider getting an account with them. They'll provide the UPS Worldship software and all the updates free. I don't know if it's because we're a very long-time customer and do a lot of business, but they GAVE me a thermal label printer to use for as long as we're a customer, and they supply all the thermal shipping labels free as well. Having that software on your computer makes it really easy to accumulate data or to look up potential rates for planning, based on size, weight and distance.
UPS Ground rate is still pretty reasonable, and while it may take a week to get something from one coast to the other, in general it will get to anything within one UPS Distance Zone overnight. For example, I'm in the boonies 40 miles south of Portland, OR, and I can ship by Ground to anywhere from the California/Oregon border to the Washington/Canada border and it is delivered the next day. With no extra effort at all on my part, I get huge points with customers for "fast service at a great price" -- and those are words I read here every single time there is commentary about a supplier.
The flat rate boxes for Priority mail are the best bargain around if you or your customers prefer the post office. While they estimate 3 days to anywhere in the continental US, I often get notification of arrival in 2 days unless it's the holiday season. You can pack one heck of a lot of soap or other B&B products in one of those flat rate $9.50 boxes, and I find it works well to encourage customers to load the box. They're often much more willing to add $10 or $20 worth of product with the idea that it's shipping "for free." That's good for sales, too! Plus, those boxes are provided free and you can order what you need, and the mailman will deliver them right to your door. Those are all little things that really add up.
