fshu, it's not easy to sample via the mail order shops; that's just the way it is. Manytrees is right about Jack Sterling's tobacco--he's a great honest seller who charges the minimal amount of shipping, and I'm smoking one of his blends right now, the Boston Whaler (if you like a mild and very flavorful aro, this is a great one to try). Otherwise you're best off saving up for an order around $100 and then you'll likely save some shipping (though not from cupojoes). If you don't have a decent B&M shop nearby you could make a leap of faith, ordering tobaccos that get good reviews / descriptions that sound like your taste preferences, and if they don't work out for you you can always offer some in trade--there's a section of the forums dedicated to this.
Hope this helps some!