Regarding your trouble with the Continue Shopping button, could you please give us a link to the page where you are testing our buttons so that we can test that ourselves? Thanks.
I've taken a look at the shipping settings in your account, you are adding packaging costs on top of a USPS Priority mail shipping rule on top of a handling charge of 5% of total shipping. With so many variables at play in your shipping costs it is no wonder that you are getting unexpected results for your orders. It is not necessary to use all of these particular options together, it would be sufficient to use just packaging costs alone without a USPS rule or vice versa, and I'd recommend at least disabling the handling charge until you are getting the basic results you want.
If you could tell us what kind of cost you are trying to match we can give you more specific instructions on what to do, so please be clear in letting us know what you want your cart to charge.
Assuming you want to match USPS Flat Rate Priority packaging, it would be possible to use packaging costs alone to get close to that. As we've already explained, our system will not switch to a larger packing type based on quantity, it will simply add in another package of that type. So it would be best to use one basic packaging type and allow multiples of that to set your costs. It will be predictable and easy to explain on your website, something as simple as $5 for every 4 items ordered. Here's how to do that:
Go to Seller Admin>View/Edit/Delete Products:
Select an existing shippable product of yours and click Edit;
Click Next until you reach the Shipping Options screen;
- Weight: Enter the weight in ounces. Don't worry about how accurate the weight listing is because it won't actually matter for this method of shipping calculation.
- Package type: Set Regular Tube (the particular packaging type is not critical, just be sure you are using the same packaging type for ALL products)
- Capacity: Enter 4
Click Next until you can Submit to save settings;
Repeat this for all your tangible goods;
Go to Seller Admin > Cart Shipping Settings and set up the following:
Shipping Origin: select your country and enter your zipcode;
Shipping Destinations: if you will only ship to certain countries, select them in the list, or otherwise select nothing for Worldwide shipping;
Set ALL package weights to 0.00. Set the price of the Regular Tube (or whichever packaging type you used for your products) to 5.000
Click Next to save settings and proceed to the Shipping Rules screen.
On the Shipping Rules screen select and delete all shipping rules you have created. They will not be necessary.
Note that the USPS Priority shipping rule available on there screen does not get the flat rate packaging prices and always returns a different rate depending on the buyer's location. That's why you have been seeing different prices for different zip codes. If you want the same rate for all destinations in the US it is important not to select any of the USPS calculators for shipping rules (or just not use shipping rules as in the above instructions).