I have not bought anything from a nursery for awhile since I do my own cuttings, if you want to plant inside your enclosure I suggest seeds, they take a little while longer to grow, but they are cheaper and you can control what you give to them.
I agree to wait 6 months, buy organic, or grow from seeds. Just because the store doesn't spray anything doesn't mean the grower didn't (and that is where the bugs are which they need to protect from, in the field, not the store). Unless they are growing organic plants, farmers spray them so they look pretty. Best wishes.
I have worked in a greenhouse, and you can count on they will put something in the spray and mist, and it will last a good long time in your plant. Just like commercial Xmas trees after Xmas, my goats do NOT get them to munch on, too risky. The same for old bouquets of flowers, don't even think about it!