366238 price comparison

require approx 5 mysql dbs ; 5 php functions to go with the mysql dbs. dbs - products, categories, products_to_categories, shops, products_to_shops 100 products ; 4 shops ; 15 categories ; 100 products to categories ; 400 shops to products (including a price column) functions - to find 5 prices given 1 product to find the cheapest of the above items to find the dearest of the above items to add the total of more than 1 item for the 5 shops. e.g. 20 items to find the cheapest basket over all and to give the products of that basket and their shop