'Dont have money to teleport' is one weird reason to ask hydra to be purchasable. If we were to sell Hydra for 50k ECD as in your suggestion, you can use teleport cmd over 16000 times for the same cost of Hydra. It's just 3 ECD per teleport.
Anyway suggestion denied, Hydra are meant to be used for the bomb drop feature. We add limit of 3 hydra and time limit based on their last use to make sure they will not be excessively used which will ruin the game. If we allow players to buy hydra, players can easily bypass the limit and use the bombs as much as they want. Anyway, they are already 82 different type of vehicles that you can buy:
http://ec.thijn.ovh/vehicles.php for transportation/hunts event. Click '$ Show/hide model cost list' to see the vehicle models that are purchasable and their cost. You can use the filter box to filter for vehicle you want..