Need a 50 gallon Weekend Warrior fresh water tank

Thanks, the tank is black
I called Ronco in Tustin and they have them for $514
I've tried a lot of fixes including plastic welding, water weld adhesive sealers, even 15 coats of flex seal
the only thing that remotely worked was some thick gooey duct sealer an AC friend gave me to try.
There is a guy near me that repairs tanks, do you think it could be repaired after all that stuff I applied to it?