I agree with Ursula.
Abigail, the orchids at Safeway or Walmart, do not know where they are being sold. They would know that they are some how unhealthy.
BUT, what you must look at, and look for, is a plant that may have sat anywhere for too long. If it sits too long, the roots may really dry out and suffer.
Remember that if you buy from an orchid vendor, presumably they take care of their plants.
Compare that to Safeway, Walmart, or Home Depot who offer plants on consignment. Do these people at these stores, including Trader Joe's, water the orchids correctly. Do they water on time or correctly??
If the plants are fresh, meaning that they have not sat there too long, they should be fine.