If it's the customer's responsibility to pay attention to the 4-6 week ship date, it's probably worthwhile for the seller to actually read the Google Checkout order management policies http://checkout.google.com/seller/policies.html which require you to capture funds within 7 days of authorization, and ship within 24 hours of capturing.

His "4-6 weeks to ship" appears to be in direct violation of the Google Checkout policy; you can't do fulfillment on that sort of timeframe if you want to bill with Google Checkout.