We are sorry you paid more for the plugin you refer to before it went into our current sale. As you probably know from our emails though, plugin sales are driven heavily by promotions. We try our best to offer high quality software at competitive pricing, but we hope you understand that we can’t refund older invoices every time a plugin goes on sale again. It’s pretty typical for plugin prices to go down over time in various promotions, but we are sure you have been able to enjoy and use the plugin successfully already during the time you have owned it.”