I'm sure that buying your orchids from a reputable grower is a surest way to get healthy plants.... However, if you actually take your time and look around, you will find some crazily cheap plants out there that are DECENT, if not more!
One time in the past, I've seen a specimen size of Paph. parishii in 8 (?) inch pot that was sold for under $50 (cant remember the exact value). The tag was bury deep within the pot that I had a hard time pulling it up. At that time I had no idea about Paph, so ... there . Now I'm thinking about that I regret for not buying that wonderful species.
I also had a Phal. Leopard Prince from Lowe's for $5 just because they'd just finished blooming. Fair condition, the leaves were still in very good shape.
Another time I went to Tom Thumb supermarket and I found this nice blooming specimen of Oncidium Twinkle with 12+ bulb and IN SPIKE! It was tucked in the middle of a flower basket along with African violet and Ivy. I asked the florist if I could buy that plant by itself because the whole basket was 45 bucks. So she took the 'chid out and sell it to me with the price of $3.50!!!

....This is crazy!!! I've just seen it for sale at some website for $20, NOT in spike. Some one please explain this to me lol