I've no experience buying from Mann Lake, though I have heard good things about them. BUT...they are the only company that I have heard people say to not buy an extractor from or to state they regret buying one from. :?
Having said that, you have Rossman across the state from you and Kelleys up north in Kentucky. They pretty well bring orders to most large meetings in the area. If you have a large regional beekeepers meeting in your area you could get them to deliver your order to the meeting (no shipping expenses)....you might check with them and see if they go to these meetings. Brushy Mountain and Dadant are normally at the meetings but I'm not sure they bring orders with them...I've wanted to order some things before for meeting deliveries but they don't get the word out in time so I order from Kelleys and Rossman...
McDonough, GA - Georgia Beekeepers Association Fall Meeting Sept 8-9 (I saw this one on Kelleys calendar)(GBA also has a spring meeting in February...this year it was in Newnan, GA.)
Cookeville, TN - Tennessee State Beekeepers Fall Meeting Sept 28-29 (I saw this one on Kelleys calendar)
Cullman, AL - Alabama Beekeepers Association Picnic in May (I know these 2 vendors go to this one)
Montgomery, AL - ABA annual meeting the first of October (I know these 2 vendors go to this one)
Auburn, AL - Honey Bee Symposium in February (I know these 2 vendors go to this one)
Is the $400 difference an apple to apple comparison or is it apples to oranges? You might want to pick up the phone and call Rossman's about the pricing...worse thing they can say is "no". Also, Rossman carries the "Italian" extractors. I believe these are the "SAF"(?) brand. My mentor has a 9-frame SAF and it is a fine extractor...looking at the website they are more expensive than the Maxants and Dadants. Maxants are built in the USA...I don't know about the others and uses premium grade stainless with high quality welding (no caulking, from what I understand). With the size investment that you're about to make I would definitely research the quality of the equipment *and* the quality of the after-sale support.
Best wishes on your search,