Excel Data Grouping a better way to roll

[JJJCR_FOX]

need your help to roll a better way...
i created macro to group a data with same value..
and group them in another column
col a - data to be group
col b - reference value
col c - grouped data with same value
like:
Col A Col B
R1 10k
R2 5k
R3 3k
R4 10k
R5 3k
R6 5k
R7 3k
R8 10k
R9 5k
R10 10k

Col C ' where data with same value will be group like:
R1, R4, R8, R10 ' All got 1Ok value
R2 , R6, R9 ' All 5k value
R3, R5, R7 ' All got 3k value

i search col b for same value and erase the value in order not to
duplicate the grouping..

is there a way to group data without erasing the reference value?
any input is greatly appreciated..

below is my code so far..it's working.. the only thing it deletes the reference value at col b

thanks..

Sub x()
Dim x, y, z As String
Dim i, icount As Integer
Dim lastrow As Integer

icount = 1

lastrow = Cells(Rows.Count, 1).End(xlUp).Row

For i = 1 To lastrow + 1

x = Range("b" & i).Value
'Range("c" & i).Value = x
If x = "" Then
GoTo out
End If


 
While icount <> lastrow + 1

 y = Range("b" & icount).Value
 
 
 If y = x Then
  
  z = Range("a" & icount).Value
  Range("c" & i).Value = Range("c" & i).Value + " " + z
  Range("b" & icount).Value = ""
 End If
icount = icount + 1
 Wend

out:
icount = 1
Next