Just some general thoughts, even if the original question doesn't stand...
Taking on a rescue is very worthwhile. Make sure it has a clean bill of health, unless you're in a position to take on an animal that needs potentially costly vet treatment.
Be very careful with quarantining a rescue. When buying from a reputable shop, breeder or dealer, it is in their interests to sell you a healthy, pest-free snake. If you're taking on a rescue, there's a possibility that it is carrying things that won't necessarily have bothered the previous owner.
As for longevity, Corn Snakes easily live to 15 years in captivity and as our husbandry techniques improve, we're seeing more healthy 20 year olds and the occasional 30 year old. If you're buying a hatchling now, you really are taking on a long-term commitment that might last longer than a lot of marriages. In my case, my eldest Corns have outlasted two long-term boyfriends!