Is it a good idea to put money in keywords e.g. 'Name of Item from £30'
Will google not register the pound sign therefore registering 'Name of item from 30' which could be anything
I just did a quick test and $30 returns different results to 30, but £30 does not (even in the UK). So it seems Google does not understand the pound symbol but does understand the dollar.
You can add hidden mark-up to content that adds semantic meaning to it, such as mark-up that states "this is a price and it's in GBP". schema.org is a good place to start learning about that sort of stuff.
Here's a small snippet of html that shows the sort of thing you would do:
This would normally be placed in context with more mark-up that indicated what the price related to.
There are no guarantees that Google will use this information, however, Google is pushing it's use and I believe will be enhancing it's support over time.
One known use is that you can mark-up a product and it's price. This information may be used to give you an enhanced listing in search results. Called a rich snippet.