That's not a completely fair example, though, for a number of reasons.
If you think there's an honest chance that a $1500 independent review could turn up something that would make you turn down the deal and try to find another, do you then expect to have another $1500 review done? What expectation should you, a non-expert in doing this kind of calculation, have about the total cost of having independent reviews done?
Also, $1500/$1million sounds tiny, but nobody who thinks they can't afford a $1500 review buys a $1million house in cash; they get a mortgage and expect to pay $4.5k/month, and people in general don't save (or have the ability to save) as much as I do/would. So it's $1500/$4500 in the immediate future of having to make your first payment, on top of closing costs, etc., for benefit that is already unclear to a non-expert.
And by definition we're talking about a non-expert, because that's why they would have the need to hire a lawyer to do an independent review.
Anyway, it's not that I necessarily think lawyers are that expensive across the board, but the existence of that perception shouldn't be very confusing. A non-expert doesn't have the tools to accurately put a value on expert services.