I don’t know how I missed that. Right there’s the biggest clue that you’re looking at a trailer. Modular homes that meet local codes will happily be financed by the vast majority of banks and mortgage companies.
If the current owners are the original owners, that there’s a warning sign. You said the place was built in 98; that means they’ve owned it for 7 years–and it hasn’t appreciated enough to pay off their mortgage? Unless they overextended themselves on home equity loans, or they weren’t the original owner, this would make me very, very nervous…
If people tell you that you can close tomorrow, tell them you can just as easily close next month.
Almost everyone involved–from the real estate agents, to the loan officers, sellers, and insurance agents–benefits to varying degrees from selling this home to you as soon as possible. However, it doesn’t sound like buying it as soon as possible is in your best interests, and it doesn’t sound like it’s a market hot-potatoe. So, no matter what you decide, take your time and do your research. Don’t get rushed into it.