The requirements are much less invasive in Michigan... But, still have to collect and pay sales tax.
I have, on occasion, tried to sell orchids at farmers markets or other roadside venues. It isn't worth my time, at least in the rural areas. I suppose if I was trying to sell at one of the really large markets (Ann Arbor is a good one), it would be worthwhile. But, I second the difficulties in selling plants outside. Orchids blow over at the slightest breeze.
I sold some outside my house last Mother's day and I bought them dirt cheap. In the end I made too little money for the work. There are people all over this town selling orchids on the side of the road and apparently some of them are making money. Try it, you might like it.