1.
 MERGE tbl AS target
USING tb2  AS source
ON (target.id = source.id)

WHEN MATCHED and source.price >450
then
UPDATE SET TARGET.price = SOURCE.price,
TARGET.group = SOURCE.group

 2.
 update tb1
set
tb1.price=tb2.price,
tb1.group=tb2.group from tb2
left join tb1 on tb1.id =tb2.id
where tb1.id =tb2.id
and tb1.price>450