I have magento 1.9 shop with 2 language (English and Russian) and 2 currency - Euro and RUB (Russian rubles). Currency rate setup correct and in product page I see correct price for both currency.
But in advanced search I need select products by Price, dependency by currency.
Now this search work normal only for one of currency - RUB.
Then I switch to English site, search result for Price show me products with my wishes price, but in RUB, not in Euro...
For example - products have a cost 6300 RUB, in my currency rate it's equal 100 Euro.
In Russian version of site everything works fine, but in English I setup Price to 100 Euro. In results I see all products with price unlit 100 RUB, instead of 100 Euro.
Site Search on Magento is not one of their strongest features. Most of the configuration settings like currency, fall well in place in the category navigation within the stores. Probably also why we saw this opportunity and developed a Site Search extension to fix this opportunity.
Also, as a platform I think they want the ecosystem around them to bring in extensions/solutions to improve the product vs. having an inbuilt solution. Hence customers like yourself have a plethora of choices to choose from Tagalys or others to fix it. While everything may not be 100% on Magento, with the extension partners, you should have options to make your Magento installation perfect. Happy to help if required.
Now I again back to this problem and I think it's bug of core of Magento (
I made some tests on demo sites and found some bug in all sites.
For example I make search for price from 8 to 10 (USD and EURO - dependence in language store)
Search result correct only for USD store (EN), in Dutch store (with EURO) we can see wrong products.