It is smart to evaluate your position with this. My first bike was $300 wayy back when. After I found I enjoyed riding, the parts swapping began. Geeze, sounds just like car stuff.
All schooling and you'll pick it up fast enough. You already have your MTB riding experience.
BikesDirect certainly sells a lot and they participate on several forums. They do offer a good value in the usual generic Chinese made frames with quality components. I was looking at the entry level offerings since you began this discussion. I'd say go for it either from them or used.