Had a catastrophic failure on my big block with oil and radiator fluid intermixed. Had to get flushed and was told I need th radiator re-cored due to leaks that showed up after the flush. What would be a fair price for such an endeavor?

Thanks!

I have not personally had to do this, but costs seem to vary widely.  So I would say shop around, get prices and compare recore price to replacement (if that is a viable option for your Vette).

Best to check around at reputable radiator shops for a price as was mentioned there can be a range.

If a replacement is in order look for one with a copper core.  While aluminum ones may be lighter my mechanic contends that one with a copper core does a better job of heat transfer.

From the DeWitt's website.

It's been a long time since 1969. The radiator has served you well. "Be Cool" ,  "Dewitts" , Corvette America can make you one. The new one will give you peace of mind when 195 shows on the gauge. It very well may cost you a significant amount of money opposed to new to recore.  

I just had mine done as I am having the engine rebuilt and same as you when they went to flush it and clean it leaks, had it recored 4 row copper with my tanks and top and bottom so basically looks factory, totaled $850.00

That's pretty close to a brand new DeWitts all alumimun black painted big block radiator, and it cools 30% better.

yes but I wanted to keep car with original  components and it didn’t come with aluminum 

It's painted black. You can't tell the difference.