I totally understand wanting to make your money back and your nervousness to spend it.
GHI's are about 5k now and by the time you have hatchlings approximately 1-2 yrs GHI's are gonna cost maybe 2500-1500. On that note, it means you want hatchlings as soon as possible and as many as possible. At 2500-1500 a lot more small time breeders would be willing to buy the gene. Demand would still be pretty high at that cost and you would easily make back the money spent on the GHI. In 3-4 years GHI's would cost probably 1000-700 dollars maybe even less. I believe at the 1000-700 dollar price range not many people are willing to buy in, since the breeders who are smart know the market is getting saturated. GHI combos at this point are now affordable and people who can are turning to purchasing those. In 5 years GHI's now cost 300-500 dollars and everyone can afford it due to a saturated market. This is also a good price point because the everyday hobbyist can now afford the snake, so while there is a huge market there is also a huge demand. Of course this is all based on speculation, but speculation is better than having no speculation and dropping 5k on a whim.
Based on what I said, I suggest a plan for you. Here's the plan.
Get 2 normal breeder size females that way you can make back the cost by selling the single gene GHI's as soon as your animal is ready to breed (1-2yrs). 2 good breeder sized normals (approx 2000g+) will produce 8-32 eggs a clutch. Let's say they produce on the low end at a total of 8 eggs that turn out to be GHI's. you could sell those 8 eggs at 2500-1500 a piece and make 20k-15k, that's alot of money, and that's the low end!
I know what everyone is thinking now, that's not gonna work, what about incubators and food cost, you'll never make money back on snakes blah blah blah. Making money off snakes is always a controversial topic.
Incubator DIY. 100 dollars
Food- for 3 adult sized snakes 6 dollars a week 30 dollars a month 360 a year.
Rack- for 3 snakes, you don't need a rack yet, 3x container store tub 30 dollars
Hatchling rack, buy it when you get your eggs. You don't need a hatchling rack if you don't have hatchlings. Approx 200.
Initial cost $5800
Including 1 ghi, 2 big normal females and tubs.
Upkeep- 360 a year
Total cost is 6160.
You can easily make back all the money you put into buying this within 2 years if you do it right! This is just the numbers I put out for you, but YOU have to do it right to make your money back and that is the hardest part.
Breed
?????
Profit!
Here's a video of Mike Wilbanks and his thoughts on this.
http://www.youtube.com/watch?v=bYrHOBB5zoY