Hi there. You are creating whats called a circular reference - the line of code you have written will put that formula into A2, so A2 will be trying to calculate a result based on itself. If you want the result as a formula in another cell, change the first A2 to where you want it to be. If what you are doing is trying to look at the contents of A2 and replace them based on what is in there, then try this:
Code:
If Range("A2").Value = 0 Then
Range("A2").Value = "Base Bid"
Else
Range("a2").Value = "Alternate - " & Range("A2").Value
End If