check out local building contractors and supply companies, they might be willing to discount or even donate labor / materials for their name on the dugouts. I gotta imagine it could not take more than a couple of days for them to assemble two cinder block / wood frame / chainlink dugouts ) I would do cinderblock kneewall in front, half wall on sides/rear, rest wood frame, prefab metal panel roof. Maybe checkout companies who do the metal garages etc.
For painting again see if any local suppliers will donate paint, have team and/or boosters have a painting party. maybe allow all those involved to autograph the dugouts in paint.
For painting again see if any local suppliers will donate paint, have team and/or boosters have a painting party. maybe allow all those involved to autograph the dugouts in paint.