I think the pricing is way too steep. Other projects on Kickstarter usually charge about double the game pre-order price (say, in FTL's case it was 10$ for the game and 25$ for the game + early beta access). Obsidian is using the factor 7, which in my opinion is too high - especially as that tier is linked to loads of rubbish that I personally have no use for (game maps, digital guides, whatever). I'm not wealthy, but I care about the game and I'd love to be a beta tester. Having a reasonably priced no-frills tier that offers just the game and beta access which is chosen by lots of backers would in sum most likely yield more money than having a rather expensive tier with only few backers at that level.
This assumes, of course, that Obisidian cares about the money and is willing to lure people with beta access. If this is not the case (i.e. they only want "quality" beta testers), then I don't understand their current move to attach beta privileges to backing tiers at all. They should rather keep beta and Kickstarter distinct and choose their beta tasters the old-fashioned way. Disposable income and beta testing abilities have nothing to do with each other.