This oversimplifies things and only makes sense in a narrow vacuum.
For starters, devs also need to take into account the market they operate in.
If they feel they should get 3.50 for their note taking app, they could pick the 4.99 option from the tier list, but if their competitors primarily price their app at 2.99, then that's another consideration to be made.
As an aside, this is why developer darling Panic, has such a hard time in the mobile app department, they weren't willing to price their mobile apps at a price comparable to their competitors (or that of mobile apps in general) and instead opted to price their apps around a more classical desktop price point. Leading them to pull most of their mobile apps in the end due to lack of success. There's a whole discussion to be had here on the devaluation of software, but that's a bit outside of the scope of this discussion.
In any case, your hypothetical seems to already been disproven.
I've seen many indie devs share their acceptance into the small business program, which slashes their commission rate in half.
Additionally, as you may or may not know, many indie devs have somewhat of an affliction that leads to them being more likely to using the apps of their fellow indie devs. I myself, "suffer" from the same affliction, and as such I've noticed that none of them have lowered their price as a result of their commission rate being cut in half.
While this is by no means an empirical study, it seems to imply that things aren't as cut and dry as "lower commission == lower price". Suggesting that there's more involved in a developer's decision than just the commission rate.
The above is by no means a dig at those indie devs, I myself haven't lowered prices either. It's merely an observation shared in service of the debate at hand.
Whatever the outcome of an empirical statistical analysis will bring, the Small Business Program is undisputedly a way to put theories such as yours to the test, in particular because the the commission rate is so drastically lowered (from a statistical POV).