I have a question for you guys. is it cheaper to rebuild a 352 or a 390?

I know that they are basically the same block and that all FE engines are $$$ to rebuild. I'm just trying to find out wether or not i should rebuild my 352 or buy a junked 390 and rebuild it? and also is it true what they say about FE's its cheaper just to buy a crate motor instead of trying to rebuild one?

thanks for any answers,
John