Just stopped by my local state government department of revenue office and ask them about how to go about requesting sales tax receipts of certain businesses in my area under the FOIA act. I was told that "I don't think those records are covered under FOIA, but you can try contacting the main state office". Is this true? Are public sales tax records requests not covered under FOIA?
Sales tax records for an individual business are probably protected (or exempted) by FOIA authorizing legislation as competitive business records. With that information, a competitor could determine quite a lot about an individual business.
Much like an individual's income tax returns are not public, you'll probably not be able to drill down to the level you seek.
Look at this site for details of each state's FOIA rules: http://www.nfoic.org/state-freedom-of-information-laws
All public records are covered by FOIA, except for those exempt by stipulation, which in my experience varies for each organization.
These could be exempt in your locality, but I highly doubt it. I'm assuming that you are in Colorado by your avatar, so here's Denver's sales tax records for the last year: