St. Louis is 48% cheaper than Richardson.
When comparing St. Louis, MO and Richardson, TX, the overall cost of living indices are 66 and 128 respectively (national median = 100). Rent is $847/month cheaper in St. Louis, saving renters about $10,164/year.
Median household income is $40,978/year higher in Richardson. Home values also differ significantly — the median in St. Louis is $185,100 compared to $405,600 in Richardson.
Texas has no state income tax, giving Richardson residents a significant tax advantage over Missouri's 4.95% rate.
St. Louis vs Richardson — common questions
Other cost of living comparisons for St. Louis and Richardson