This might sound a little crazy, but there are several very large world-wide trade websites that importers/exporters use on a daily basis (ex. Tradekey.com). I have been looking on a lot of these sites and have found a lot of companies out of Egypt, Brazil, Jordan, that not only have hatching eggs for sale, but also 'Parent and Grand parent stock'. Most of them claim to be Ross and Cobb.
Not that I am speaking for the quality of these birds or that you are really getting what you pay for, but.... I would think some of these companies would be more likely to let their parent stock eggs go for less than a larger breeder in the US would.
That being said, you would still probably need to spend a lot of money initially because they aren't going to ship 13 birds. I just think you could probably end up having to buy less than if you contacted Cobb or CWT farms directly.
I don't know much about this business but it seems to me that if you want to secure the parents to produce your own hybrids, then you pretty much need to be at the point of bulk production.