Try this code to get your solution:
create table Bidhistory
(
bidid int,
bidprice int
)
insert into Bidhistory values(1,100);
insert into Bidhistory values(1,50);
insert into Bidhistory values(1,100);
insert into Bidhistory values(1,50);
insert into Bidhistory values(1,75);
select distinct MIN(bidprice) from Bidhistory
Output:
50
and then try to bind it gridview