We went to Venture and had a fantastic time. We spent �1500 (!!!) and yes, we both had to be at the viewing, but the children were not invited - I agree, I think it's a hard-sell type thing.
Some local photographers now offer the Venture-style photos at a fraction of the cost, so if you like the style but not the cost, it might be worth looking around your own area.
That said, the big picture we bought is beautiful, and we don't regret the cost at all. If you treat it as a once-in-a-lifetime, I'd recommend it.