How are you determining when the pot is dry? The finger test for example isn't that reliable. Emilya recently made a good post about watering and when:
The Proper Way to Water a Potted Plant
And I personally don't like perlite, it holds a ton of water. I think people mistakenly add it for drainage, but IMO it can make things worse.
You could call Roots Organic, maybe ask them about your problem or how long the soil nutrients last on average. It might be depleted of all its nutes and ready for manual feeding.
Sure, start another seed. But I wouldn't throw this one out. Keep it going as long as you have space for it, while you wait for the new one to grow. It might turn around. I'd let it get bone dry and when it's starting to wilt, give it a good pH'd feed.