Yes you can do it, this idea came in the mind of web developers and they developed some new techniques through which two websites can talk.That's what we call web 2.0.Now how to do this?
There are lot of ways.But it is always better to sign up with the service you want to use.For example Amazon offers books store information to other websites for free.For using this you need to sign up with Amazon as developer and get a API key and a API.This API can be used with any of the programming languages because it recieves XML.Similar services are offered by google and they have powerful php support in form of zendgdata. Some sites offers php api using curl() and fsock().These can be risky unless you know you can trust the site.Another way is to read RSS and extract the information, RSS feeds are in xml format, so they can be used to get such info using any language.It is a worse idea to open a website page with your program in background and then parse it to get the price.This will be waste of bandwidth of your and siteowner and as well as may fall under copyright violation.
Edit:- You wrote, it is static which I couldn't see on my mobile phone.So then you have to do what lemontree told you.