Hi,
I have a slightly different proposal. I can provide this as a service to you.
I write scraper scripts in PHP. So my PHP scripts will be scheduled to run everyday at a pre designated time on my server. Once it finds a difference in a website, it will store the details in a database table. Once all the scrapers are completed, another script will run which will combine all the differences and send a consolidated report to you over email.
Like I said, this will run as a service and hence for a monthly fee of 50GBP, you will have a surety of continued support for this script. In the other case, if the website layout changes, the scraper will break and you will no longer have a working alert system. If you prefer to run this system on your server itself, without the monthly support, I can do the same for 250 GBP one time fee.
Let me know your thoughts.
Thanks!
PS: I didn't find any csv attachment, so I am not sure how many sites are in the scope here. If you can send me, I can check them and provide a sample.