Hello Enpanales,
Sorry about your pricing issue with product attributes. I would need a bit more information to understand your issue. On my PrestaShop installation the issue does not occur when adding attributes to items. Could you provide specific details about one of the affected items and give the exact way you are creating it?
I also see on your site that some of the items have attributes and their prices seem to adjust accordingly. Were you able to resolve the issue on your own?
Kindest Regards,
Scott M