The real answer is : it doesn't matter, unless you set it way too high. The economy will adjust until the value of basic income is equivalent to a particular value.

Now of course, what could happen is that you set it too high and we get massive inflation and dollar devaluation for a few months/years.

The reverse should also be true. Because fitting within basic income will massively expand client base for companies, there might actually be devaluation if it's set too low.

I think it's pretty obvious that one cannot choose the level of basic income. You can only do damage by choosing wrong. Given that it's currently zero, if you'd want to do this, start at a very low level (but still high enough to make companies want to provide services at that level), work out the kinks, and increase it over the course of a few years slowly until you see undesirable phenomena, then stop. Ideally, make this a state thing so regional differences can efficiently work.