Regardless of what the sales people are telling you all home sales are negotiable especially at this point in the economic madness. In order to negotiate you need to bring something to the table that makes the deal sweeter for the other party. Example - a bigger down payment - a higher credit score to give them greater security - a faster closing date - etc....
The facts of life on repos are that they cost the bank money every day they own them. A repossessed home is a non-performing asset for the lender. Not only are they nor making the money from the payments but now they own a home that they have to cover for insurance, taxes and any expense needed to maintain the home in sellable condition. There is a daily cost, higher than most people might assume, associated with each and every home that is in the banks repo inventory.
In almost every case the bank looses money on a repo. The rule of thumb for most remarketing managers is "First loss. best loss". It matters not what the bank may do, they will loose. As that loss grows daily it is best to stop the bleeding and get that home off the repo inventory. So a no negotiation policy would go against the best practices of the banking/lending business.
Many lenders set their resale prices based on percentage of their investment. I have found that most are hoping for a 75% return. For example if they have $100,000 invested in a loan they will set the resale price at $75,000. This is just a good rule of thumb. There are lenders that shoot for a higher or lower recovery, depending on times and home condition. Lenders expect a certain level of repossessions and have a budget to cover those expenses... BUT In times like these when most lenders have more repos then they are comfortable with, they will generally lower their target price to reduce their repo inventory. If you have a way of finding out the amount owed the lender you will have the most valuable info for negotiating a lower price.
21st Mortgage and Southern Energy are both owned by Clayton Homes. Clayton has emerged as the class act of the MH industry with its conservative financing and fully integrated business. You tell us that your credit is "not good". In that case a repo is your best chance of getting financed. More than once I have been able to get a loan on a repo for customers that could not qualify for a new home. Unless you have some way of increasing your credit rating you would be wise to shut down all noise about a new home and concentrate on making the best deal possible on a repo.
Talk to the dealer about the extended warranty type service contract. It is a great advantage to you and the seller to have the house covered so the seller never has to deal with or even hear about any problems after the sale.
21st has most of their repos listed, with the price they hope for, online HERE
See if you can find the home your shopping or others that would work for you that are within 100 miles for a first hand picture of what is available and the prices they are willing to take.