cheaper coupling caps on a budget

hi, I don't know about you but it seems that all of the latest capacitors out there have become so expensive that I can no longer afford to try them. I am looking for a coupling cap for my tube amp that has high resolution but without grain or glare, I dont really like oil caps , they sound to rolled off for me. Does anyone know of a cap that sounds as good as [ fill in your favorite expensive cap here ] but that is cheap, I will need 8 of them, and they are 2.7 value, at 500 volt, thanks, chris