How would you know same amount of money is needed to do the upgrade? Chinese weapon sales do not operate like Russian or Western. They charge very competitive prices for their military export. I can be sure Bangladesh military did their homework well before making any purchase.I meant with that price tag 100-120 without upgrading them now if you want to upgrade you have to add the same amount of money to make them lethal that bring the total cost to a quarter billion since new radars and other systems like ciws that's what I meant.
The Russian are very famous for charging exorbitant prices for upgrading while after sales support is very bad.