Product price is VAT not included but accessories price is VAT included

[Seashop.eu]

Hello dear community !
I am a new person here, not very experienced with coding, and that's why requesting your assistance.
I am building online shop for marine electronics ( www.seashop.eu ) and now at a stage for adding products.
The only problem i find is that my all my products are listed with prices where VAT not included. But when i add accessories to the product, the price for accessories are listed with VAT included. This is a link for the exact page with problem http://www.seashop.eu/product.php?id_product=18
Could you please to find my mistake and help me with the issue ?
Thanks a lot
Regards
Costas