> Also UBI is funded by taxes
Some of those taxes are already being paid. We have a lot of social programs that, for what could politely be called "political reasons", include extensive administration whose primary function is gatekeeping and means testing. Often, the administration of those programs costs substantially more than any money "saved", leaving aside that it also has a very high false positive rate, excluding people who actually should have received it. But there is a political faction that would rather see government burn a billion dollars just to make sure a tiny fraction of that isn't paid to someone who didn't "deserve" it. To quote https://www.bitsaboutmoney.com/archive/optimal-amount-of-fra... , "the policy choices available to them impact the user experience of fraudsters and legitimate users alike. They want to choose policies which balance the tradeoff of lowering fraud against the ease for legitimate users to transact."
Eliminating entire programs and the massive administrative overhead of those programs, and replacing them with something that merits the label "universal", is much more efficient.
Also:
> on a nationwide scale it means everyone got x% more money and the market would adjust itself accordingly by raising prices?
This is assuming the injected money has zero multiplicative effect on the economy, which is very unlikely to be the case. By way of example, since we're on a site created by a startup accelerator: Many, many people have said that UBI would be a massive boon to the startup ecosystem, by making it possible for many more people to safely try to build a startup without as much personal risk.
Analyses vary, but some analyses have suggested that UBI may be a net benefit to the economy. At the very least, economic boosts provided by UBI substantially offset its cost. That's in addition to the offset mentioned above of replacing existing less-efficient programs with UBI.
> improved an ACA, a cap on healthcare costs for all if you will and free yearly health checkups.
We should do this as well, because healthcare is one of the few things that isn't addressed by UBI (since ultimately it's an insurance mechanism).