Why don't you contact a "Certified Indoor Environmentalist" in your area or certified mold specialist to take a look at the house. Make sure you get someone who is truly certified and doesn't just say they are. If the house failed inspection, then most states require the seller to disclose the items that failed. Have you asked for a Disclosure statement? Mold is one of those things that the jury is still out on. It was a huge deal a few years ago, and can still be depending on the type and quantity of the mold issue so you'll want someone who knows what they are doing to take indoor air samples and have them sent to a reputable lab to determine if there really is a problem or not. If the home was built in 1957 has it been tested for lead paint and asbestos as well? Those would be the other issues that would concern me, as well as any structural ones. I would say that even if it costs you a bit of money, if you are serious about purchasing the property you should have the testing done to determine exactly what you might be getting in to. Is this a short sale through a bank or is there a realty company involved? If there is a realty company then I would think they should have the info regarding why the home failed the previous inspection or whatever caused the deal to fall through.

Good luck!

Here is a link that might be useful: Certified IE link

Mold remediation can be very, very expensive and inconvenient. Expect to spend thousands, and to tear out lots of walls, flooring -- and then to find unexpected problems hidden behind the drywall, or under the carpet. And in the end you need to have the air indoors tested to ascertain whether or not the mold concentration levels are below minimal acceptable standards.

It may still be a good buy after taking these issues into account -- PROVIDED the source of the mold is clearly determined and found to be a one-time cause like a leaky pipe inside the walls that was fixed, or something like that. HOWEVER, if the cause cannot be determined or if the cause is not easily correctable, then make a U turn as fast as you can.

I'd have to really love it - and I'd find out why the last deal failed after inspection...it might have been nothing more than the seller being unwilling to make the repairs, and the buyer was unable to affect the repairs themselves even after an allowance was taken on the price.

I'd be under the crawlspace (gloves, goggles, dustmask and all) and looking for sign of pooling water - I've seen places where downspouts have wound up channelling water into the darndest corners...

another to check is to take the covers off the wall outlets, and check the 'inside' of it, and the cavity, for spores - it's the one place a casual bleaching isn't going to reach, for starters ;)

which is something not all inspectors, even fancy mold-hunters, are going to do.

mold is every bit as scary as the web sites make it out to be...but that doesn't mean that the web sites aren't scare-mongering, staging or enhancing shots, and padding their estimates like hell...

I'd get two or three opinions - but if my sinuses didn't snap shut after 20 minutes in the house? it's no worse than the swamp I grew up in :)

My advice - pay the few hundreds of dollars it costs to get a mold check done - read the results, and walk away if there is a problem. Write it in on your offer that the offer is subject to inspection & mold test. That's what we did on our 1889 home with a musty basement. Clear test - no worries. Bad test - ask for a price adjustment to cover the cost of the remediation or walk away.

My opinion - "old houses" built after WWII will not last as long as those built before - the materials and construction are different. And when you start looking at additions...who did it and how well was it done? You may find a nightmare once you start monkeying around.

And for DIY stuff - I have a hard enough problem with dusty jobs throwing my respiratory system into revolution - I pretty much shut down around real dust or mold. If you are going to demo the basement yourself, you need to consider if you are going to be able to complete the job and also the cost of the demo if you have to quit due to health reasons.