price checker

looking for a someone to develop a price checker. the software should be able to check our competitors site for a price change then email us. 1) we enter details of OUR product url and price and select if this is including VAT or excluding VAT 2) the program checks that url and finds the corresponding price 3) we now can add multiple urls and prices and specify if they are inc or ex VAT 4) the program will email us once their price drops below our price 5) we can specify when the checks should occur ie once a day . twice a day when we change prices on our site it will not email us and only email us if the price changes on competitors site. someone may have developed a better program or may have a better idea please put this forward.