^ I'd just like to know where you can get a pre-owned Omega for $500! The only ones I've seen under $500 are more than 50 years old.
Well for under $500 it might be 40-50 years old, thats true, but thats also part of the magic

A vintage omega is a beautiful thing. You have to look beyond what you see sometimes and picture it with a different band or slight polishing, but I just love them.
I have a local dealer who usually find really really nice original ones and sells them for $400. They are ALL over ebay. which I would only recommend if you know what you are looking at, know the movement calibers and the how to look up serial numbers to check year accuracy. Being familiar with case backs, dials, and crowns helps here too.
There is also a watch forum where people can be very helpful as well as a sale forum where one can pick up a minty seamaster.
For example...I ~almost bought this one earlier this week, but the crown isn't original and the dial was redone. Still..I wanted it...till I realized how much I really wanted a metal band :-P
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rt=nc&nma=true&item=290519386577&si=LpycJarAZf91ei5nUr7nl4pJlJU%253D&viewitem=&sspagename=STRK%3AMEDWX%3AIT#ht_5394wt_907
geez...now that I see it again..I wish I would have bid higher. Oh well And:
http://cgi.ebay.com/RARE-1970-OMEGA-SEAMASTER-VILLE-CAL-601-6-X-SIGNED-/250694420696?pt=Wristwatches&hash=item3a5e8d48d8#ht_3668wt_907
here is an Omega Quartz..which I wouldn't get just because I wouln't spend that much for a 40 year old quartz Omega..at that point I'd want an automatic movement, but:
http://cgi.ebay.com/s-sOMEGA-SEAMASTER-Mens-Quartz-Watch-70s-Cal1342-MINT-/360332874154?pt=Wristwatches&hash=item53e58351aa#ht_8329wt_907
there are lots more on there in the middle of their auction time. It seems most with re-dials go for around $250-350, originals are obviously more. It just depends what you want.
http://cgi.ebay.com/COLLECTABLE-VINTAGE-OMEGA-SEAMASTER-AUTOMATIC-MEN-WATCH-/270689443797?pt=Wristwatches&hash=item3f06591fd5#ht_6763wt_1141
If vintage is your thing coolvintagewatches is a good site to purchase watches (they have some older omegas around the $500 mark there too)
If vintage isn't your thing, then for under $500 I would stick with what i said before: Sieko, Citizen, Tissot, and maybe even Invicta (I have a womans one and it is an outstanding watch)