I know I am about to get destroyed here, but I don't see the issue. Sure you don't need any particular wheel to race, to compete in races, or to win races, but that wasn't the question. OP never asked what wheels are needed for racing... etc.
OP is looking for something new, plans to use them racing, has a price limit and wanted to get some input from some pretty seasoned people. Seems fair to me. Now, that said, the variables involved make one "right" answer impossible... but if OP has money and wants to spend it on wheels, that's why they make them.
What I was more impressed by was the stunning generosity of his LBS being willing to rent him some 2010 404s for his races. What do you figure, $200 per weekend? Cat 5, one, maybe two races per weekend? Factor in a few DNFs for whatever reason and you have maybe $2k in rental fees before you hit Cat 4. I'd find another shop, if they recommended that I don't think they have your best interest at heart. Sure, they are a for-profit enterprise, but cummon...
I'ma go put on my flame suit now.