I buy the best product I can find for the money I'm able to pay. So, I guess quality of the product is really more important than price, but since a great deal of quality varitation is present at any price point, it is ultimately the dollar amount that plays the decisive role. If money were no object I'd buy strictly on quality: the best whether it cost $100 or $100K.
Auditioning equipment is important, but it's really meaningless if side-by-side comparisons of various products and manufacturers cannot be made in an acoustically equivalent environment. Shelling out a ton of money up front to purchase several different products for an in-home audition period is impractical to say the least.
Customer service is extremely important as well, and is always something I mention when recommending a product or manufacturer to a friend.