Walmart had it on sale on their website for 349.00. I just looked and now they are out of stock.
I just bought this exact camera about a month ago. I got it at Circuit City for 344.00. They price matched walmart's price of 398.00 and then took off an additional 10%. You might want to call them and see if they will PM walmarts price and beat it.
As for online dealers, I know what you mean by "reputable". I found some shady characters when I was searching.