Berg's Radiator does a great job of re-coring radiators and the cost is worth it.
I purchased one at French Lick and report favorable results!
Now, with shipping and handling, it might cost more than having a re-core done locally, but I'm not so sure.
It was going to cost me over $500 for a re-core from a local radiator shop (specializing in older model automobile radiators), so it would have been a wash I guess.