Wrong rich snippet price tag (when using "discount function")

[TOSch]

Hello,

We encountered a problem in the displayed price tag by google, in his rich snippet text.

The best is, we give you a description of the problem by providing you an example with a specific product of our shop.

This is the product's page:
http://theonlineshop.ch/en/teeth-whitening/8-glamwhite-home-bleaching-elite-kit-7629999018280.html

As you can see, the diplayed price should be CHF 98.00 (base price of CHF 169.00 minus CHF 71.00 discount = 98.00 VAT inclusive).

If we check the page in the Google Structured Data Testing Tool (https://developers.google.com/structured-data/testing-tool/) we get no general problems and the displayed price is effectively CHF 98.00.
BUT if we check the structured data in the google's index results, something is wrong with the price tag, because in the google index, the displayed price is CHF 85.48 and not CHF 98.00.

After some calculation we found out that Prestashop is calculating this price by the following way:

 

Base price of CHF 169.00 / 1.08 (VAT in Switzerland is 8%) minus discount of CHF 71.00 (incl VAT) = 85.48 (excl VAT) this price dosen't make any sense to be displayed because why should Prestashop do this calcualtions by taking a base price incl. VAT, deduct the VAT, deduct  discount incl. VAT and keep this price as the final price??

Here you can check it out in the google index (should be in the first page, at position 4, but it can may be different for connections coming from outside of Switzerland since we focus exclusively on the swiss market):
https://www.google.ch/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=home+bleaching+kit

We didn't find out where Prestashop is calculating this price. We are using Prestashop 1.6.0.14.

We would be very grateful for an answer and a possible solution since it's a bit confusing for our customers who find us in the google index.

Many thanks and kind regards

[TOSch]

We managed to find a solution and I will post it here for anyone who encounters the same problem:

 

The fact is that if you set a specific VAT rate for your customers in your specific country (geographic restriction) than google will most probably get a wrong VAT information, because the google bot who crawls your website is placed around the world in different countries (yes, not only from the US). Basically the solution is to set the VAT amount for each country so that if google access from a specifica country, he can perform the correct calcultions based on your price, your discount and the legal VAT.

For Switzerland: if you choose to sell only in Switzerland and you will avoid this problem: just set the geotargeting as usual to exclude buyers from abroad BUT set the Swiss-VAT for the entier world.

[kmorgen]

Noticed same problem

 

But if setting the local VAT to be in effect for all countries, this would also mean that visitors from other countries will see the price including VAT - even thought they are from a country which should not be charged the VAT (for example outside EU). So this would then have a huge negative impact on conversions?!