It's worth noting that none of us are entering the hobby, and we're only hypothesizing in what a theoretical newbie would be willing to pay.
And that the amount the people claim they're willing to pay when asked is almost always significantly less than the amount they'll actually pay when push comes to shove.
I'd actually like to expand on these two points to give my take on it: I don't really count the "freebie" cost of "invite a friend to play" as "cost of entry" -- you can invite a friend to play at your golf club, and pay his fees for him too every time he comes along, but without you, sight unseen, his cost of entry is more like Cost of Basic Clubs & balls + cost of club or organization fees, which are somewhat prohibitive; it's why most people who enjoy golf as a hobby are middle-class or higher, and plan budget accordingly.
I believe when discussing "reasonable cost of entry" we need to discuss it from the standpoint of the cost of a medium, much like the various box sets for the early 80's, which not only had attractive enough production values and enticing enough ad copy but was low cost enough for people to be pulled into it by initial purchase alone. Back in the day, that cost was $12.00, or about $30 or so adjusted for inflation. Any cost you can get into it for less than this is a serious bargain, anything a lot more than this would be exorbitant to me.
To this end, games like savage worlds have an excellent cost of entry: about 10 bucks for the book, and another 10 bucks for the dice, and you get a beautiful full-color book, well-explained rules full of play examples, and plenty of art value to spark imagination. It's too bad Fiasco doesn't have a distro deal with various book chains, because with a little bit of extra art, it's rule set is similarly evocative and well-explained, and without a bunch of odd dice to buy as extras -- just buy a couple of bags of regular dice at a Dollar Store, and you're set.
I agree that with the RPG model, word of mouth is essential to keeping the hobby alive, but to be a true growth medium, it has to be able to still appeal to people who find it on their own and find something interesting enough in it to give it a try.