we feed ours chicken layers pellets (some people recommend crushing them up first, but ours managed perfectly well !) & crushed maize, cereals.
Japanese quail (cortornix) are good layers, and fairly hardy, but they won't lay during the winter.
Get them as young as possible, this way they'll get more used to you and reduce the risk of escaping, and bear in mind they have a much shorter life span than chooks.
as for prices... you're better to check locally as it will vary! Are you wanting eggs? day olds? layers?!
Katie Thears book on quail is quite informative, or an internet search of 'corturnix' or 'quail' - You can buy eggs from 'Game for anything' site. There are also some forums with good information pages.
hope that helps...