I'm not sure what you are going after.  If this is a display issue, you may want to handle this in your front-end.  Otherwise, I do not see the problems you are having and I would absolutely not use "float". 

DECLARE @Money TABLE( Price money)

INSERT INTO @Money

SELECT 1

UNION

SELECT 1.01

UNION

SELECT 1.001

UNION

SELECT 2.5002

UNION

SELECT 2.5101

UNION

SELECT 3.001

UNION

SELECT 4.5202

UNION

SELECT 2.515

UNION

SELECT 2.5555

SELECT Price, CONVERT( decimal(5,2), Price) AS [ Price 5,2], CONVERT( float, Price) AS [ Price float], ROUND( Price, 2, 1) AS [ Price Round ]

FROM @Money