The above may well be true, but don't get confused in thinking every IR approved school has an ILS and/or NDB on the field somewhere.
For me at Stapleford, I had to fly down the road to Southend to do the approaches, which was only 10/15 mins and we joined controlled airspace to get there, so it wasn't as if we're wasting time.
Back to the question, if you're asking, you're obviously considering going somewhere like the school I went to. I think £1k is a good figure. Pretty sure if you do a full IR 55 hour course in minimum hours, it's horses for courses - the £1k extra you spend on one course, still comes up as the same or less then a school who doesn't charge but 'include' this fee?