I'm just a novice here, but I've played Motorstorm and imho it's a fairly "meh" game, so you aren't really getting anything there.
I don't know what kind of glasses it comes with, that would make a difference in value. Passive (no batteries) glasses cost around 30 bucks, active ones can cost as much as 60. The hdmi cable is one of those 2 dollar deals so no value there.
Just a completely unbaised opinion from a guy that doesn't even like sony products.... it's all about the monitor. If you think a 24 inch monitor is big enough and you think the quality of the monitor is pretty good then it seems like a pretty good deal to me. A 24 inch, 2d tv is around 200 bucks, so 300 for a 3d version isn't bad at all. If the monitor stinks then it's a crap deal because the stuff they bundle with it is fairly worthless. IMHO 24 inches is a tad small for gaming unless you are going to be sitting fairly close to the monitor. (Think pc gaming.)
Regarding tax.... your mileage may vary but generally how it works is if there is a brick and mortar version of the store in your state you have to pay tax, otherwise you don't. So yeah, you'll pay tax at Best Buy. That doesn't mean you won't pay tax at amazon though because amazon often sells things from other stores through their marketplace.
I hope that helps some!