Apples and Oranges. I'm talking rates, you're talking dollars. People in MA make and spend more money than people in Alabama, so you'd have a higher per-capita tax burden even with lower rates in MA.
Per capita income minus dollars taxed or the ratio of the two might be a better measure than either of ours for what you're trying to get at.
Point being, the rates are low and could easily be added to without dumb-ass industry specific things like this.
Whether the sale of customized software is subject to sales tax or exempt, you're going to have "industry specific things like this".
This sort of software is in something of a hazy middle ground between shrink-wrapped software on the shelf and IT consulting services. Taxing it may seem dumb to us when compared with other states, but probably seems like a reasonable move to at least consider to most.
Per capita income minus dollars taxed or the ratio of the two might be a better measure than either of ours for what you're trying to get at.
Point being, the rates are low and could easily be added to without dumb-ass industry specific things like this.