Which items sold by Stew will net a profit when resold to Jani? And what determines when will Stew change the item he is currenty selling?

Question

Stew is an NPC that sells items cheaply. However, he only sells one item at a time.

Which items sold by Stew, will net a profit when resold to Jani (a merchant buying and selling at normal prices) (and assuming the player character is wearing the Wastelander or Crimson Elite armor, which both give a 5% discount on all cash purchases)?

Stew regularly changes the item he is currenty selling. I also would like to know: What determines when will Stew change the item he is currently selling?

The RAGE wiki already lists some of the items sold by Stew that will net a profit when resold to Jani, but I'd like to know about the rest as Stew regularly changes the items he is selling.

Answer 1

Partial answer to the first part of my question:

Item — Buying Price from Stew — Selling Price to Jani — Profit
(prices are with the Wastelander or Crimson Elite armor, which both give a 5% discount on all cash purchases)

• Authority MG Rounds — $20 — $26 — $6
• Bandage — $10 — $12 — $2
• EMP Grenade — 3 pcs. for $30 — $10 — (no profit)
• HE Grenades — 5 pcs. for $14 — $4 — $6 per 5 pcs.
• Viper Rockets — $66 — $75 — $9

Some of the items listed here are from the 'Stew' article in the RAGE wikia. The rest are from gameplay experience.

Feel free to suggest an edit to this answer to add more items, or comment if you reckon it should be a Community wiki.