Do you have any economic analysis you can point to that show commodity prices will inflate significantly under UBI for more than a short period of time? This is a criticism I see often from opponents of UBI, but I've yet to see an actual economic proof for it. In the real world prices generally tend to converge over time based on margins rather than on what people are willing to pay. It's not clear that UBI would immediately increase cost of production for commodities, so basic competition in markets suggests that prices would largely stay the same. This, of course, doesn't hold true for things like housing and healthcare that exist outside normal economic markets.
It's also worth noting that there's a good chance UBI would act to reduce the hours worked by a significant number of people such that their total income remains the same as before. For example, if your target income is $50k and you're having to work two jobs today to make that much, the result of UBI for you would most likely be that you quit one of your jobs, still make $50k total, and use the extra time to have a better life. I don't put much stock in the idea that everyone who receives UBI will immediately turn around and use it as additional discretionary income rather than changing other behaviors that have knock-on economic effects.