threshold amp

I recently got a threshold stasis 3 amp.i might have made a mistake, does any one know if this amp is worth upgradeing being it will cost around 1000.00 bux.its a very clean piece but I paid 900.00 for it.should I sell it and buy a better model threshold for about 1500.00.my problem is if I upgradeit I don't know how far up the threshold chain I will have gone. anybody have any idea where the upgades would take it to? thanks glasspak