You may pay around the following prices, scientific names to avoid confusion (common name) and my rating for ease of breeding:
Turnix melanogaster (Black Breasted) around $200 a pair is fair but can go as high as $300 and as low as $100 - supply and demand
- IMO moderately easy to breed
Turnix varius (Painted) around $100-150 a pair and somewhere in between
Turnix velox (Little) around $80 a pair but give or take about $20 at times - IMO moderately easy
Turnix pyrrothorax (red chested) have no experience but have heard as high as $400 a pair and would love to have some if anyone has them
Coturnix pectoralis (stubble)$40-50 pair
Coturnix ypsilophora (brown) $40 pair
Coturnix chinensis (King) $10 - IMO don't let them breed - aviary rats
Turnix maculosa (Red Backed) Don't know but would love to find out and love to have some
Turnix castanota (chestnut backed) $??? as above
Turnix olivii (buff breasted) $??? as above
These will vary pending which state your in and where the pendulum is in the market trend of supply and demand.
Hope that helps