My Son has been one of 7 for the last two years in a Student house/lodgings, where all 7 have shared his BT line and Nildram (which became Pipex and is now part of Tiscali) Broadband wired and wireless internet connection.
Students tend to make massive downloads and often breach the Fair Useage Policy of most Broadband Suppliers, which will in the case of most Companies, cause them to restrict your Broadband to a fairly useless level per month, as punishment.
Nildram as was then offered a full (up to) 8k - no-one ever gets 8k, it's more like 1 or 2k if that and if you're lucky in parts of London 4k, completely unlimited commercial monthly package, normal fee £70 per month. On special offer in November 2007 at half price for the life of the Contract, so £35.00 per month is what is still being paid.
Plus of course you need either a BroadBand Cable connection, or an "unshared" BT line to the property and there is the concomitant monthly rental cost of the Cable or the BT line and the risk that some of your other 8 housemates might be tempted to use the telephone running up a telephone call cost as well.
In my Son's case, the agreement is/was, NO OUTGOING telephone calls on the landline. full stop.
You should start approaching BroadBand internet Companies and ask them what they can offer you at what cost and what background assistance there is, when your internet goes down, without having to pay £1 plus a minute premium phone rates?
Do some research on the internet - the WatchDog BBC programme recently (a few months ago) ran some scathing attacks on internet companies on their WATCHDOG programme. Have a look at that, to see who not to purchase your Broadband from.