Two questions:
(1) would trying this with products that don't include anything physical alter the effect?
(2) how ethical is it to use the Decoy Effect?
I am not really sure why ethics would come into this discussion. Do ethics come into picture when you are considering/selecting databases or programming languages?
edit: rephrased.
This is easy said than done though, depending upon what business you do.
Normally, I like to test pretty much everything (start with 10x, compare with 9x/11x maybe) but when it comes to prices, I personally feel A/B testing them is a bad idea.
does a metered pricing fall into value? meaning if someone generates 1000 reports should it cost them 100 dollars? what if it's an all or nothing situation. the value comes from when they receive most of the 1000 and no value when it falls lower than 300? does a metered pricing make sense in this case or does a monthly subscription makes sense?
So if your user benefits by making an additional $100 by using your product, you charge him $10.
For example, if you have an accounting app that saves the customer $2000 a month in manual bookkeeping, then your app should cost $200/month.