Flintoff, Tendulkar, Soeib etc didn't come through the ranks. But we're talking about 'still' somewhat test-baby (!) Bangladesh. Playing A team matches are of utter importance and should be looked at with proper care. Bar Australia and South Africa, everyone else are keen to give their talents and fringe players A team match exposure for smooth transformation to international fold.
As some posters suggested playing quality league cricket in Australia and England would help too.