it might be sufficient to set oxblfixedprice = 1 for all articles in the table oxarticles of the shop’s database: http://docu.oxid-esales.com/CE/sourcecodedocumentation/4.6.8.88988/details_8php_source.html#l01219
That’s the checkbox " Deactivate Price Alert " in the “Extended” tab of the product in the admin panel.