HOW MUCH YOU NEED TO EXPECT YOU'LL PAY FOR A GOOD UG8

I just concluded just one D104 venture wherever i gutted the head and replaced it by using a lower z dynamic factor from a junky Cobra CA73 hand mic. Im also converting a T-UP9 stand to non amplified.I actually similar to the looks, and the peak is correct to be used for the desk. But I understand that the aged condenser mics degrade eventually, Wh