I want to point out that getting all these recipes isn't for people who have limited time, or have a limited amount of gold. At the time of my purchasing, I spent a grand total of about 45 gold in order to gather up all the samples and to purchase the recipes out right. Tag on all the spore samples you'll need just to make some of these recipes? Well, it's a bit of a cost in time or gold.
To get started you need to turn in 50 Pristine Toxic Spore Sample to Marjory Delequa and the best way to do that is to turn in the five you get from finishing the Living World story, and to go hunt out the Toxic Spores that will spawn all over the map. At these Toxic Spores complete the event to get the harvest node (which can be gathered via a copper gathering tool or better) and start collecting up fifty spores. After turn it all in and you will get access to the merchant window.
Alternatively, for those of you who like to do PvP and want to avoid the PvE side of all this, you can also spend 750 Glory in the Mists to purchase a Toxic Seed Box. This box can only be purchased 5 times per reset per account. While not time efficent you do get a few Samples, and a chance at the Air-Filtration-Device skin that isn't available to PvE-only players.
To get all of the Recipes it will cost you 2,500 Pristine Toxic Spore Samples and 10 gold. Though I recommend you only spend 1,500 and stick to a single Sigil and Rune recipe as they all require the same materials to make across any of the professions.
The Healing Tome: Antitoxin Spray is good to purchase here ONLY IF you can't get the 25 skillpoints on your alts. Most of us should be able to considering all the skillpoint scrolls rolling around. Truly not cost or time effective.