I always advise against purchasing pre-extracted harmalas as the quality varies quite a bit and we've had hundreds of people report getting bunk material. It's really simple (and a whole lot cheaper) to just extract your own or make tea from rue or caapi, and this way you can be sure of what you are getting.
That dosage is quite a bit higher than most people would need or want to go, especially without previous experience. Always start on the low end and work your way up. You can always take more, you can't take less. In general dosage for acacia confusa root bark orally falls within the 6-10 gram range for most people and harmala dosage falls in the 100-200mg range with purified material (keep in mind harmaline is more potent than harmine if you are working with one or the other instead of both) or 2-4 grams of syrian rue or 50-100 grams of caapi.
Be safe now.