Thanks for all the comments!
I just have to ask, have any of you that suggested ebay actually looked? :-)
The prices on Ebay have gone up so the $300 budget is completely blown there, even with used kits (ok, I have not looked at many "used" kits but come on, it is for a birthday present

)
I will keep my eye out but even in the Seattle area where I am I have not seen a Mindstorm kit on Craigslist in the past 7 months (I have been looking for other Lego kits).
Maybe some of you know corners of the web that may have old inventory that don't show up on web searches? Maybe you know of a local toy shop that still has some stock on their shelves?
I am hoping maybe so.
