Well, I hate to be the bearer of bad news, but I think the price guide will eventually move to only values from the United States, like it was at the beginning of BrickPicker. Values from outside the US have always been difficult to acquire and aggregate. Many times there are language issues/conflicts that affect the way the information is gathered and utilized. Honestly, there is just not that much demand for these values outside of the United States.
There is another issue as well...money. We have never charged anything for the data, but it costs us a substantial amount to obtain it. Affiliate advertising has changed tremendously over the past decade. eBay basically pays us nothing from what they did 10 years ago. Target is done paying us. Toys R' Us never paid anything. Skimlinks and Amazon are what basically keeps the site running and that is barely enough.
The US secondary LEGO and reselling market is much larger and viable. This is just a fact. I wish we could give you exact values for all 10,000+ sets in the database, but that will never happen with data from outside of the US. With the differences in currencies and languages, it is just too difficult to make the non-US data perfect. Unfortunately, it would take a substantial monetary and time investment to make this work. This investment is not a worthy one at the moment...Sorry.