I would say the biggest obstacle would be the work/time involved. Weeding is time consuming and digging and dividing for sale is hard dirty work that can be underestimated until you start doing it. I would not start with seeds because you will find that not all seedlings are worth keeping and daylily people probably won't be all that interested in buying unnamed seedlings that you don't want to keep unless and until you become a well-known hybridizer. If the primary reason is to sell, you would be better to start with named cultivars IMHO. You may find that the general gardening public will pay for "a pink one" or "a red one" but they won't want to pay a lot for them. Don't look at the high prices of well-known hybridizers' new introductions and expect to get the same until you are one
