Sum of a column giving wrong results

Here's my SQL:

;Test1 AS
(
SELECT 
  C1.Col1
, C1.Col2
, C1.Col3			   						
, C1.Col4
, [Status] =
	(
	SELECT
	CASE 
	WHEN 
	[Status] IN 
		(
		 'Ind'
		,'Act'
		,'Bor'
		)
	AND Col4 = 'Activated'
	THEN 'Dispose'
	ELSE [Status]
	END
	)
, C1.Col5
, CASE WHEN C1.Col2 = 'Used' Then C1.Col5 ELSE 0 END AS [UCost]
, CASE WHEN C1.Col2 = 'Borrowed' Then C1.Col5 ELSE 0 END AS [BCost]

FROM
Cted C1
AND [Status] IN
  (
      'ABC', 'DEF', 'GHI', 'Dispose'
  )
)
 
 Select 
  C2.Col1
, C2.Col3
, SUM(Case When C2.Status = 'ABC' Then 1 Else 0 End) As [Tr1]
, SUM(Case When C2.Status = 'DEF' Then 1 Else 0 End) As [Tr2]
, SUM(Case When C2.Status = 'GHI' Then 1 Else 0 End) As [Tr3]
, SUM(Case When C2.Status = 'Dispose' Then 1 Else 0 End) As [Tr4]
, SUM(UCost) As Cost1 -- Gives me wrong results, seems to multiply the cost twice
, SUM(BCost) As Cost2 -- Gives me wrong results, seems to multiply the cost twice
From Test1 C2
Group By C2.Col1, C2.Col3
Order By C2.Col1

When I run my query the SUM of my cost is giving me wrong results. Can you direct me in a right direction? I want just 1 row for each Col1 (I am getting that), the columns are getting loaded properly, but its just the cost column that's giving me a trouble.