Realistically you are talking £2.2K for this trip, most of this is the fee to join the programme, which includes most of the costs between arriving at Mer de Glace campsite on the first morning and leaving a week later.

However the programme necessarily changes - mainly due to the weather conditions but also due to the condition of the group - for example we descended after our acclimatisation treks into Italy and there was a cost associated with getting back through the Mont Blanc tunnel, which of course, we all shared equally.

The detail's below.

Programme Fees: 1700 Euro (Note the 2013 MBC is priced at 1900 Euro per person)£1334.77
This includes all guiding, campsite fees, one return cable car ride up to the Aiguille du Midi and all Hut stays with meals described in the iteinery. Its wise to plan for additional cost for extra meals, huts and cable cars (overall it was an additional 215 euro for me) - getting up Mont Blanc is not straightforward and plans are likely to change due to the weather and condition of the group.
Getting there: 
Return flights Newcastle - Heathrow - Geneva£300.64
One consideration is when to book a return flight - if the weather is poor but good at the end of the course Stefan could decide to continue the course to give members the chance to reach the summit. However if you book a return for a few days after the course finishes you need to be prepared to stay on in Chamonix (or perhaps at the campsite as I did) if the course finishes on time, this may add extra cost. Flexible flights are another option b ut you normally pay for this in the cost up front. 
Return transfer to Mer de Glace campsite - I used Chamexpress, I've used these before and they have always been good quality, punctual and sensible when it comes to changing plans.£51.04
Gear rental: 
As I was flying into France I decided to hire the pieces of equipment that were difficult to transport by that method. On reflection I would have preferred my gear and would do this next time.
Ice Axe£5.00
Unplanned costs: shared between full group - single share: 215Euro£168.79
Lunch at opening meeting 
Additional stay in hut - 1 night - with 1 additional lunch 
Cable car fare into Italy 
Transport Italy, Cormayeur to Chamonix 
1 addditional ride up to Aiguille du Midi 
Group meal at Campsite x 2 
Grand Total£1873.24