St. Louis is cheap, but it's cheap for a reason. If you think 6th and Market is bad, take a stroll through East St. Louis. It has the 3rd highest murder rate in the country. Violent crime is on the rise. [1] Basically, it's one of the most dangerous cities in the country.
If that sort of thing doesn't bother you, then you'd probably be better off just moving your startup to Oakland and maintaining a connection to the Bay Area startup network. Or, if it does, move to a more modern, safer city in the South that still has a low cost of living without many of the economic problems of the rust belt cities (and better weather to boot!).
Have you lived in St. Louis? East St. Louis is not St. Louis. I lived in St. Louis for the better part of 27 years (Tower Grove South, St. Louis County, Central West End, and Boulevard Heights) and never had any problems. St. Louis is a city of neighborhoods, just like many other places. Some areas have higher crime than others, but to categorically call the whole town dangerous isn't fair.
Having grown up in St. Louis, I will say that the statistics about violence are highly skewed. Yes, the rates of violent crime in East/North St. Louis are extremely high. However, it's not terribly difficult to avoid these areas (unless you're really into strip clubs). The suburbs and most of the rest of the city are no less safe than comparable areas in the bay area.
I grew up in the area too, and moved back a few years ago. People often give me weird looks when I say I live on the Illinois side, assuming I'm living next to Pop's or something. The Illinois side is all really nice farmland if you just go a few miles out from the city. That is one of the nice things about Saint Louis. I grew up on several acres of land, my dad was able to commute to downtown in less than 30 minutes, and he was able to afford that on a mid-level government employee salary.
East St. Louis is really a separate topic from St. Louis; the name is just coincidental. That said, when I lived in St. Louis, East St. Louis was the destination of choice for carjacker-rapists who would take their victims across the bridge and dump them in some industrial parking lot.
St. Louis is currently listed as 3rd highest violent crime rate in the country (Detroit is #1, but in years past St. Louis edged out Detroit for murder rate). I'm not saying don't move there, but just be aware that north St. Louis is a pretty bad area and the economy doesn't seem to have improved much, despite the massive investments into the central urban attractions like the Arch, Union Station, and the things listed in the OP.
Perhaps the main problem with St. Louis is the division between the actual city of St. Louis and the various suburban towns that surround it. In 1970, the city boasted a population of nearly one million, and just 3-4 years later it was down to about half that. City residents blame the population implosion on school busing which led to white flight. The burbs like Clayton, Webster Groves, etc., in St. Louis County ("the County" as people call it) had their own tax base and when affluent people flocked there, the city lost a substantial portion of its tax revenue.
Overall, I really liked St. Louis but the crime rates are pretty bad. The weather in the summer is also bad -- very hot and humid. You will need AC, and it doesn't come by default with every dwelling. If it were me, I'd be looking at Phoenix or Tucson, because of their proximity to southern California and of course the weather, but then I spent some time in Arizona and fell in love with the place. Cost of living is probably comparable if not cheaper than St. Louis as well. Can't speak for the start-up community in Phoenix, however; there's not much of one that I heard of, as of 2010 or so.
>> Basically, it's one of the most dangerous cities in the country.
If you're worried about the violent crime rate, don't move to the south. Texas, Florida, and Louisiana are always near the top for violent crime rate. The states with the lowest murder rates are in the north, generally. You want to move someplace like Vermont or Oregon.
East St. Louis is a different city, across the Mississippi river and in a different state than St. Louis.
St. Louis has taken its share of knocks over the years like many Midwestern cities, but those crime statistics are not indicative of the normal experience here.
If that sort of thing doesn't bother you, then you'd probably be better off just moving your startup to Oakland and maintaining a connection to the Bay Area startup network. Or, if it does, move to a more modern, safer city in the South that still has a low cost of living without many of the economic problems of the rust belt cities (and better weather to boot!).
[1] http://www.nbcnews.com/business/most-dangerous-cities-americ...