On closeout (40% off already lower prices) a Tiagra groupset from CRC costs $453.80. The doesn't include things like rims, spokes, tires, nippes, seat post, stem, headset, saddle, handlebar, tape, pedals and odds and sods.
If they're talking 105 and all the extra stuff for $1,000 it doesn't sound too bad. Heck, my road wheels are $1,780 LBS retails...