I don't know when I first bought Rosetta Stone, but I do know that I have two editions of it (one for my old laptop and one for my current, less old laptop), or possibly three (because I got an update link from support when I was having trouble with my current version. The second version I bought January 2011; the first version I bought in March of 2007 (am I that organized? Oh, dear goddess no; Amazon remembered it for me).
The last time I was in the Netherlands was in spring 2004. My previous efforts to learn Dutch involved Dorling Kindersley's Hugo Dutch in Three Months and Taking Dutch Further. I was so cheap at the time (I was dating a grad student who was uncomfortable with the amount I spent on things and thus constantly looking for less expensive/free ways to do what I wanted to do -- ISLAGIATT) that I got Dutch in Three Months from the library (which an _excellent_ way to teach yourself Dutch and I've seen reviews that suggest the rest in that series are also good), and I went through it so fast and demand for it was so low that I didn't even have to return it/pay a fine -- I was able to renew enough times to finish. I bought Taking Dutch Further in 2004 for the 2004 trip because I wasn't able to get what I wanted through the library that time.
I've bought dictionaries (Dutch/English and also a child's woordenboek), books, a Dutch grammar in English, one of those collections of verbs, etc. I tried to take a class in Dutch, but even when I was in Seattle I failed. I'm currently attempting to connect with a teacher here (there's a Dutch school in Boston aimed at Dutch and Belgian kids who hope to re-integrate in the Dutch school system when they return home), but I'm not optimistic. I'm not currently willing to give up a half dozen Saturdays to a language class.
When I was last in Seattle, I took a couple rounds of German at a place then located in Pioneer Square. I do not recall how much I paid for the classes, but I remember it being hundreds of dollars. When I look at what is charged for classes from the same operation now (Washington Academy of Languages, and it has apparently moved and is now attached a university), they now want $405 (more if you want the college credit). The 3 level Dutch course through Rosetta Stone is $399 whether you get it from them directly or via Amazon.
While I can't speak to the current WAL offerings, and I took German rather than Dutch through WAL, I think you would learn _at least_ as much Dutch for $399 from Rosetta Stone as you would for $405 from WAL (if they offered it, which they do not). I would argue, actually, that the amount of Dutch you learn through the 3 levels is roughly equivalent to between two and three classes at a place like WAL -- potentially a significant savings, however, you might want to discount for the fact that the humans teaching a course at WAL or elsewhere can insist on you getting the accent correct whereas you really can game the voice recognition through Rosetta (but then, CD and tape courses _never_ had any kind of voice feedback either). Also, the instructor would hopefully get the meaning and usage of things like A.U.B. correct, which, alas, Rosetta Stone totally fs up.
I conclude from these experiences that while, obviously, there are a lot of ways to learn to use a language at a level above please-thank-you-how-much, Rosetta Stone is _not_ an unusually expensive way to do it and it _is_ an unusually enjoyable way to do it.
I've also done some googling around on not-in-English websites which sell books/kits/software/etc. to learn languages (mostly Dutch ones, because, hey), and have ordered two of the EuroTalk levels through Amazon, also a Prisma self-study book + CD. While it may well be the case that learning Spanish through Rosetta is a terrible decision (I wouldn't know), because there are so very, very, very many alternatives, with a language like Dutch, there just are not that many choices and most of them enjoy widespread agreement that they are not as good as Rosetta Stone.
Even on Dutch websites oriented towards learning other languages.