2 Red Gathering Tokens (1 mining, 1 botany) should be enough to get you hand in materials for 2 Red Crafting Tokens. That comes out to 4 or 5 (4 one week, 5 the next) such pairs. That, in turn, turns into 24 or 30 (respectively) refined materials per week.

For example, Odorless Animal Fat. 1 Red Gathering Token for mining, and 1 Red Gathering Token for botany, should get you enough hand ins for 2 Red Crafting Tokens. Since 1 Red Crafting Token is worth 15 Odorless Animal Fats, that pair of Red Gathering Tokens should be enough to get you 30 Odorless Animal Fats. Since it takes 5 Odorless Animal Fat to make the leather, that equates to 6 refined 2* materials.

Each week you can get 9 Red gathering Tokens and 9 Red Crafting Tokens. That works out to 24 or 30 refined 2* materials per week (depending on whether the odd Red Gathering and Red Crafting Tokens are available).

Those 4+4+4+3+3+3+3 refers to the number of refined 2* materials go into each piece in the class-specific set. That works out in a general sense, but not all pieces of equipment use the same refined 2* materials. One pair of pants may use 3 leathers, while another uses 2 leathers and 1 silk. That sort of thing throws a kink into things when it comes to planning your Red Token usage. That number string also ignores the belt+accessories, which are shared by all crafting classes.