Dave,
Even with postage you will still save money. I ordered a large amount of truckmount equipment and paid $500 for deliverey. A lot yes, but I still saved £500 on £2000 worth of equipment.
There are some US cleaning suppliers I've found seem not to want your business, they either want excessive deliverey costs or just don't even bother to reply to e-mails.
Try WorldofClean.com, I found a guy named Jeff Ellis very good, kept the price down and found cheapest deliverey.
Regards