Getting Started:Before one can start with the crafting of Spark, you should ensure that you have at least the Revered Antiquarian mastery, such that you can start working on the first tier of your precursor. Once you've got this mastery, you can speak with Grandmaster Craftsman Hobbs and buy Incinerator Vol. 1 for 5 gold and 10,003 Karma to start working on the first collection. While you're here, you should also buy the recipes for Aluminum, Aluminum Bronze, Beryllium Copper, Invar, Lye & Mizin from the fifth tab for a total of 30,030 Karma. By double-clicking on Incinerator Vol. 1, you're now ready to start with the first step in the crafting process.
Tier 1: The Experimental DaggerFor the first tier, you'll need to mine a number of ores, craft a few materials & gather samples from various Dwarf, Asura, Orr, Aetherblade and Dredge related buildings. A full list of all the collection items and how they can be obtained can be found in this table.
Noteworthy for this table, is that you can follow the hyperlinks for each item to see additional information such as the location of permanent ore nodes (credit goes to /u/jetti91), solutions to jumping puzzles and locations of the various structures one needs to interact with. The minimum and maximum cost in this table were found using the current buy and sell price of the TP and this table's rows are sorted based on the order of the ingame collection (reading left to right, top to bottom).
Once you've got each item listed in this table and thus completed the first collection, you'll obtain a Chest of Industry. The contents of this chest are later needed to craft the Experimental Dagger, which is in turn required to complete the second collection.
Total approximate cost of Tier 1: 2.00 - 2.50 gold
Tier 2: The Perfected DaggerOnce you've completed the first tier, you'll need to get the Magister of Legends mastery in order to be able to continue. Once you've got this mastery, you can speak to Grandmaster Craftsman Hobbs to buy Incinerator Vol. 2 for a cost of 5 Spirit Shards and 10,003 Karma.
This collection requires you to obtain and craft a large number of items and hand them in to Master Weaponsmith Frayja and Scholar Mossi. The list of all the required items and their required components can be found in this table.
In this table, I've created three cost columns: minimum cost, non-time-gated cost and maximum cost. The minimum cost was found using the listed buy orders while assuming that the player crafts all the time-gated materials themselves. As this would take at least 60 days (you'll need 60 Deldrimor Steel Ingots for this collection), a second column is included that consists of buying the time-gated materials using sell orders instead. The last column depicts the maximum cost of each item; it uses the material selling price on the TP and a minimum amount of crafting. It is, as the name suggests, the maximum one should spend on each item. I should also note that, as this table does not use the GW2 API and is therefore only really valid as a rough cost estimate, I suggest using GW2 Efficiency's crafting calculator to determine the exact cost and to select which materials you craft yourself and which ones you simply buy from the TP.
Once you've completed the second collection, you'll obtain the Tricks and Tips for Advanced Dagger Crafting item. Again, the recipe and item you obtain from this chest will be needed to complete the next and final tier of the crafting mechanic.
Total Approximate Cost of Tier 2: 437 - 655 gold
Tier 3: SparkTo start on the last collection, you'll need to make sure you have the Historian of the Armaments mastery. Once you've got this, you may speak to Grandmaster Craftsman Hobbs to buy Incinerator Vol. 3 for a cost of 5 Spirit Shards and 10,003 Karma.
In this collection, you'll need to complete a number of jumping puzzles, fractals and defeat a few world bosses to get the items needed to complete the collection. The list of required items and how/where they can be found may be seen in the third tab of the aforementioned table.
As a number of items require previously obtained ones, I highly suggest doing them in the order listed in the table, with the exception of rows 3-8 of the table; they can be done in arbitrary order. As you'll need to bring bloodstone dust for quite a few components, it is also advised to simply bring a stack of Bloodstone dust with you along the way.
Total Approximate Cost of Tier 3: 6.00 - 11.00 gold
Crafting Spark:Once you've completed the third and last collection, you'll get the Essence of Chemistry and recipe needed to craft Spark, which can now be crafted using a Prismatic Lodestone, Spirit of the Spark Experiment, Expertise in Dagger Crafting and a jar of Luminescent Polish (again, I suggest using GW2 Efficiency's crafting calculator to find the current cost; it'll cost you between 32 to 42 gold to craft spark itself).
This brings the total cost for the entire crafting process to approximately 477 to 710 gold.
While I used Spark to craft Incinerator (which I was able to sell on the TP), I haven't tried selling the crafted Spark itself. However, I suspect that it is unbound, just like The Colossus. Especially since it has "Soulbound on Use" in it's description (instead of the "Account Bound on Acquire" both the tier 1 and tier 2 spark have). It would be great if someone could confirm this.
A few words on the crafting process itself: I've really enjoyed the entire crafting mechanic and I believe that ArenaNet has definitely succeeded in making it the Legendary Journey they wanted it to be (the mails sent by Grandmaster Hobbs for one really add something in my opinion). So, if you've always wanted to get a precursor, but don't want to play the MF or straight-up buy it from the TP for potentially more than the cost of crafting it, I recommend you to give the crafting mechanic a try! As mentioned, if you have any further questions, don't hesitate to pm me ingame (Arphelior.7013).