Really depends on the breeder. I don't like to pay more than 30-45 a pair for birds that aren't laying yet. 50-100 a pair is fairly normal for large fowl birds over 6 months I would say. But that can vary wildly. Shipping is expensive too, but it evens out in cost of feed to raise, already...
Lot of serious breeders won't sell eggs either. It's always best to buy juvenile or adult stock so you know exactly what you're getting. Usually come out money way ahead on this too.