Price and tax

As others also writed, your plugin calculating the product’s price without tax, but it’s wrong. Woocommerce has the option to add prices with tax, and show them with tax everywhere.

I have a discount plugin, it sets a product’s price from 2999 to 2249 (tax included), but in the cart and checkout, it shows 1687 if your plugin enabled (if I disable it, the price changes 2249 in the cart and checkout). It’s really wrong, you must change this.

Or the other method to add an option in the plugin to disable pricing calculations.
(I’m using your plugin for adding custom fields only, so I don’t need pricing calculations in my case.)

The best solution is to do the both.