I'm not even sure there are enough items to buy in PSN Home to add up to over $300. Unless you bought both all male and female clothing items which would be a bit odd.
Home has already reached the point where buying everything that comes out as if it were some communist state goods store is pretty pointless. Most of the stuff should really only appeal to certain tastes.
Spending over $300 on PSN in general on the other hand isn't that big of a deal. I've already spent more than that myself although I have been buying PSN games since early 2007.







