Erg. Elger Quests. And a chart D:

Account of one night of Elger Quests (not including crystals)

35k
-1
+754
------
35,753
-8
-20
+3467
------
39,192
-148
-1189
-4995
+643
------
33,503
-209
+670
------
33,964
-12877
+639
------
21,726
-24
-2935
-3593
+5937
------
21,111
-2700
-155
+906
------
19,162
-390
-265
-3333
+2063
------
17,237
-525
-2119
+727
------
15,320
-2948
-6990
+715
------
6,097
At this point, I have done 10 elger quests and lost over 80% of what I started with. I stopped my elger quests then, and put my crystals in my shop. I had
2 Air
1 Ash
2 Dark
1 Earth
1 Grime
1 Ice
1 Light
1 Digital

I priced them all exactly 10 points beneath the next highest.

Air Crystal 2 9,239MP MP
Ash Crystal 1 5,214MP MP
Dark Crystal 2 8,330MP MP
Digital Crystal 1 7,888MP MP
Earth Crystal 1 5,735MP MP
Grime Crystal 1 5,472MP MP
Ice Crystal 1 4,483MP MP
Light Crystal 1 6,858MP MP

After 10 minutes in the shop, this was the result.

1 min. - 0
2 min. - 0
3 min. - 0
4 min. - 0
5 min. - 0
6 min. - 0
7 min. - 0
8 min. - 0
9 min. - 0
10 min. - 4483

I sold all the crystals later.