Cost me about £110/hr (plus any landing fees at £8 a pop) to learn at Leeds last year. Prices haven't gone up particularly since then. Perhaps it's an economies-of-scale thing, but £142 sounds a little steep to me (disclaimer: not an expert).
You don't say what type you're learning on, but my thinking was to learn on the cheapest (152), as it only takes a couple of hours to convert onto something different once you've passed. Never understood the whole "I want a share in a PA28 when I've passed, so I'm going to learn in a PA28" attitude.
Some places will give discounts for payment up front. I'm always wary of this, even with big organisations, so only ever paid for 10hrs at a time and usually flew those 10 hours within a month anyway.