I found it! :D
ok, so, in the includes/modules/my_template/meta_tags.php,
define('META_TAG_TITLE', arrangement_of_title_components . etc)
is the code youre looking for. there are 18 of these in the meta_tags.php file, and each one sets up the page titles based on different things, namely your chosen level of customization for the meta_tags of various products and/or categories. if you've customized the metatags for your categories, for example, then you will search for // bof: categories meta tags and find the define('META_TAG_TITLE', etcetc) and change the order of the elements to whatever you like.
for those, like me, who haven't customized their meta tags, you can scroll down to line 275 and rearrange the elements in the latter part of this code:
define('META_TAG_TITLE', str_replace('"','',$review_on . TITLE . PRIMARY_SECTION . $meta_products_name . $meta_products_price . TAGLINE));
the arrangement above lists the site title, then the category, then the product's name, then price, and lastly tagline.