set nocount on
create table #t(nomer varchar( 10 ), summa int, zakazchik nvarchar( 50 ))
insert #t values('Pr1',  30 , N'Слоник')
insert #t values('Pr1',  30  , N'Кукла') 
insert #t values('Pr1',  30  , N'Баран')
insert #t values('Pr1',  30  , N'Черепаха')

select nomer, summa, min(zakazchik) as zakazchik from #t group by nomer, summa
union all
select NULL AS nomer, NULL AS summa, a.zakazchik from #t a
inner join 
(select nomer, summa, min(zakazchik) as zakazchik from #t group by nomer, summa) AS b 
on b.nomer = a.nomer and b.summa = a.summa and b.zakazchik <> a.zakazchik

drop table #t

set nocount on
create table #t(nomer varchar( 10 ), summa int, zakazchik nvarchar( 50 ))
insert #t values('Pr1',  30 , N'Слоник')
insert #t values('Pr1',  30  , N'Кукла') 
insert #t values('Pr1',  30  , N'Баран')
insert #t values('Pr1',  30  , N'Черепаха')
insert #t values('Pr2',  60  , N'Слоник1')
insert #t values('Pr2',  60  , N'Слоник2') 
insert #t values('Pr2',  60  , N'Слоник3') 
insert #t values('Pr2',  60  , N'Черепаха1')
select nomer, summa, zakazchik 
from (
select nomer, summa, min(zakazchik) as zakazchik, NULL as nomer4order from #t group by nomer, summa
union all
select NULL AS nomer, NULL AS summa, a.zakazchik, a.nomer AS nomer4order from #t a
inner join (select nomer, summa, min(zakazchik) as zakazchik from #t group by nomer, summa) AS b on b.nomer = a.nomer and b.summa = a.summa and b.zakazchik <> a.zakazchik
) AS a
order by ISNULL(nomer, nomer4order) DESC

drop table #t