works out around £2.25 per 24exp. roll by way of comparison, plus the initial / one-off cost of a bulk loader and reusable canisters.
You would almost certainly need to develop your own if you go down this route - I'd be surprised if a shop or commercial lab would touch anything hand loaded and lacking DX coding.
http://www.ebay.co.uk/itm/Ilford-HP5-Plus-35mm-17m-Bulk-Film-/251393157674?pt=UK_Photography_Film&hash=item3a88332a2a
You would almost certainly need to develop your own if you go down this route - I'd be surprised if a shop or commercial lab would touch anything hand loaded and lacking DX coding.