Here’s the XP situation based on safely returning all your non-magical treasure to Gosterwick …
Ella: 346/346
Grim: 762
Jacky: 390/390
Thrud: 692
Zach: 692
The potential XP value of your magical items are as follow (sell / keep):
- Scroll of Find Traps: 600/60
- Effervescent emerald green potion (x2): 400/40 each
- Cloudy black potion: 500/50
- Scroll of Phantom Armour: 300/30
- Codex: Property of Eustachius the Cantor: 8,000/4,000
- Luminous bone white potion: 900/90
I’ll let you do the maths, but, for example, if you were to sell all of the above, you’d end up with the following XP …
Ella: 1,456/1,456
Grim: 3,204 (enough to take Grim to 3rd level!)
Jacky: 1,500/1,500 (enough to allow Jacky to reach level 2 in his thief class)
Thrud: 2,912
Zach: 2,912
Of course, you need to weigh up the trade-off of keeping the magical items so you can benefit from them.