How many levels can one expect to get by endgame (per difficulty, of course) anyway?
That's a hard question to answer, but I've figured it out up to the Anomaly, but first, the assumption list:
* 100% kills on all levels.
* You play all the specials and get 100% kills (in this case, Arena, (Un)Chained Court, and Wall).
* No caves (reduces XP) or mazes (increases XP).
* The assumed amount of XP is based on average XP / Danger point, and as such can fluctuate.
* No vaults (which spawn extra enemies, and thus increase XP)
Anyway, here you go, expected level at Start of Anomaly (Floor 8), by Difficulty:
ITYTD: 8,645 XP = Lv 5 / 41%
HNTR: 10,896 XP = Lv 5 / 98%
HMP: 12,761 XP = Lv 6 / 35%
UV: 18,381 XP = Lv 7 / 39%
N!: 24,767 XP = Lv 8 / 34%
For those interested, the calculations (spoilered because they take some space)
ITYTD: 98 Danger Points @ approx. 30 XP each = 2,940 XP + 141 XP (Phobos Entry) + 1,239 XP (Hell Arena) + 2,207 XP (Unchained Court) + 2,148 XP (The Wall)
HNTR: 169 Danger Points @ approx. 24 XP each = 4,056 XP + 178 XP (Phobos Entry) + 1,528 XP (Hell Arena) + 1,906 XP (Unchained Court) + 3,228 XP (The Wall)
HMP: 251 Danger Points @ approx. 20 XP each = 5,020 XP + 193 (Phobos Entry) + 1,398 XP (Hell Arena) + 1,670 XP (Unchained Court) + 4,480 XP (The Wall)
UV: 402 Danger Points @ approx. 21 XP each = 8,442 XP + 257 XP (Phobos Entry) + 2,038 XP (Hell Arena) + 2,588 XP (Unchained Court) + 5,056 XP (The Wall)
N!: 501 Danger Points @ approx. 25 XP each = 12,525 XP + 310 XP (Phobos Entry) + 2,758 XP (Hell Arena) + 3,106 XP (Unchained Court) + 6,068 XP (The Wall)
Edit: Fixed a small display error.