Originally posted by @Kingsley Okwerekwu:
Are there certain major expenses (roof, heating etc.) that may be hidden from the pictures and the mls listing?
YES. Some of the problems can't be seen in pictures. Sometimes they can be seen if the picture is clear enough, but the listing agent deliberately uses a flip phone from 2003 to take the pictures of the fixer-uppers for the MLS. :D (Look at their other listings and see if the photos are better on the houses that are listed for full retail.)
You can usually see a few things from the pictures. If the listing says "central air", or you can see an air conditioner compressor sitting next to the house, but there are window A/C units sticking out of many of the windows, then the central air is broken. If the house is at the bottom of a hill or backs up to a creek, you should think about basement leaks and sump pumps. (Sometimes it helps to look at online maps or street-view images to figure out if it's at the bottom of a hill.) If the roof is so bad that some shingles are missing, you can usually see that. If there are two-prong outlets, then the wiring is older and may need updating.
The square-footage thing has been mentioned. In my area, a lot of the houses are in mid-1950s to late-1980s subdivisions, and were born at around 1,000 to 1,400 square feet. Lots of them have had part of the basement finished since they were built, which legitimately adds around 200 to 300 square feet to the living area. A few of them have had additions built on the back, which usually also adds about that much.
However, some listing agents have decided that if the basement is finished, they can just double the square footage that the county has, and list it that way. If it was built with 1,000 square feet, they list it at 2,000 square feet. The reason they do this is that most sites like Zillow, Trulia, etc, have an option to sort listings by "$/square foot", and inflating the square footage makes their listings show up first when sorted that way.
The county appraiser or assessor will have the tax records that show at least what the house was built with. In most major metro areas, these are online, and free to search - often you can either punch in the address if you know it, or look at a map and click on the property you are interested in. Usually you can find out the year built, square footage, current assessed value, and current or upcoming property tax bill. Often they will have the historical values and tax bills going back 5 to 7 years or so. Google things like "worcester county tax records" or "worcester county appraiser" or even "worcester county GIS" to find their site.
A few areas may still try to charge you to look at the tax records. In that case, there is usually a computer at the county government building, or maybe at the public library, that can search those records for free, but you have to physically go there yourself and use that particular computer. COVID-19 may have limited access to that computer, as well.