In making a buying decision like that I usually ask myself two questions: (a) how much $$ do I make an hour? (b) how much $$ do I then "spend" by using lots of hours looking around to beat a pre-existing price by a few dollars?

That's not to say that you can't save some serious bucks by shopping around (I usually do that online with a quick price compare any time I buy a new gizmo, consider shipping charges and delivery time vs. state sales tax, etc., or in-stock here or wait there, for a better price) but it's also easy to drive right past the exit called "Diminishing Returns" and not get off the freeway