Your query has some odd elements like 'meta_value_num' => '',
but it sounds to me like what you want is exactly what category__and
does.
$my_query_args = array(
'posts_per_page' => 10,
'meta_key' => 'price',
'category__and' => array($catid1,$catid2),
'orderby' => 'meta_value_num',
'order' => 'asc'
);
Side note: your price
meta key will not order in a way that you think is correct unless the associated values actually are numbers.