My perception (although I never tried it) is that it reduces the number of people actually trying it and avoids that you have to still pay for the payment platform fee when there is a refund, plus I presume there is also some dedication needed for handling the refund itself.
I speculate that there might be a sweet spot between the impulse purchase and the price level where you do not bother to ask for a refund, even if the tool does not work for you, but still it is counterintuitive for me why not to reach as many potential users as possible at a nearly zero marginal cost and sort of pray for conversion with a much higher user base.
In other words, at this price range with no recurring income, what is the percentage of users who actually to ask for a refund? Is it very low?