Hi Buhl,
I don’t think you’re crazy at all and it would really depend on how any of the online mattresses you were considering compared to any of your local “finalists” in terms of your personal value equation and on the customizing, exchange, and return policies that can lower the risk of an online purchase compared to a mattress you can test in person. There is more about how an online purchase may “fit in” to your mattress research in the tutorial post here which also has all the basic information, steps, and guidelines you will need to make the best possible choices.
There are hundreds of forum members that have made well researched and successful online mattress purchases.
I’m not sure where you live in Montana but post #5 here and post #4 here may also be useful if any of the options or possibilities are within reasonable driving distance.
Phoenix