I don't think its possible to change it that drastically. In Diff2Money.ini you can set the amount of money for each difficulty level. Not much help there..
In mbase.ini you can set the difficulty of missions at set bases.
This is from SDK:
nickname = Li01_01_Base
local_faction = li_p_grp
diff = 1<--increase to 19
msg_id_prefix = gcs_refer_base_Li01_01_Base

[MVendor
num_offers = 8, 12

[BaseFaction
faction = li_n_grp
weight = 13
offers_missions = true
mission_type = DestroyMission, 0.000000, 0.112387, 30<--increase to 32, 99, 30
npc = li0101_lnavy_001_f
npc = li0101_lnavy_002_m
npc = li0101_lnavy_003_f

The numbers just mean:
the minimum level, maximum level, percentage of this faction at this base
the highest in normal FL is 28.5, 53 at Crete/Malta so the above should give you whaat you want. But, the problem is that the factions in Liberty do not have very high loadouts and ships so only the Outcasts could give the very high level missions unless you added to their faction_prop entries.
Also, I believe that the encounter in the system is also a factor. If you have rogues at D1 then you can't expect to get 250k missions.

If you set the mission_type = DestroyMission, to 99.000000, 100.000000, 100 it will set that base to the highest possible mission payout based on your Diff2Money.ini.

J-MAN

Hi i have some problems with mission payout on Freeport 9.
I set a new mission payout and it doesnt work.
Here are my files:

Diff2Money.ini:
[Diff2Money
Diff2Money = 0, 1800
Diff2Money = 0.082100, 3600
Diff2Money = 0.112380, 6000
Diff2Money = 0.205130, 9900
Diff2Money = 0.351000, 15400
Diff2Money = 0.480490, 19800
Diff2Money = 0.657740, 24200
Diff2Money = 0.900380, 29800
Diff2Money = 1.232530, 35500
Diff2Money = 1.687200, 41000
Diff2Money = 2.309610, 48300
Diff2Money = 3.161630, 55700
Diff2Money = 4.327960, 63000
Diff2Money = 5.924540, 71400
Diff2Money = 8.110100, 80100
Diff2Money = 11.101920, 90700
Diff2Money = 15.197410, 113500
Diff2Money = 20.803740, 148900
Diff2Money = 28.478239, 195200
Diff2Money = 38.983860, 250500
Diff2Money = 53.365002, 305155
Diff2Money = 73.051361, 393800
Diff2Money = 85.051361, 466713
Diff2Money = 100.000000, 500000
-----------------------------------------

mBases.ini:
For Freeport 9

[MBase
nickname = Ew04_01_Base
local_faction = gd_z_grp
diff = 19
msg_id_prefix = gcs_refer_base_Ew04_01_Base

[MVendor
num_offers = 8, 12

[BaseFaction
faction = fc_c_grp
weight = 30
npc = ew0401_corsairs_001_f
npc = ew0401_corsairs_002_f
npc = ew0401_corsairs_003_m

[BaseFaction
faction = gd_z_grp
weight = 50
npc = ew0401_zoners001_m
npc = ew0401_zoners002_m

[BaseFaction
faction = gd_bh_grp
weight = 20
offers_missions = true
mission_type = DestroyMission, 38.983860, 53.365002, 100
npc = ew0401_bounty_001_f
npc = ew0401_bounty_002_f

[GF_NPC
nickname = ew0401_bounty_001_f
body = pl_female2_journeyman_body
head = sh_female2_head_gen
lefthand = benchmark_female_hand_left
righthand = benchmark_female_hand_right
individual_name = 220992
affiliation = gd_bh_grp
voice = rvp541
misn = DestroyMission, 38.983860, 53.365002
room = bar
bribe = gd_z_grp, 10000, 16102
bribe = gd_bh_grp, 10000, 16101
rumor = base_0_rank, mission_end, 2, 133201
rumorknowdb = ew04_to_ew03_hole
rumor = base_0_rank, mission_end, 2, 133202
rumor = base_0_rank, mission_end, 3, 133203
rumorknowdb = ew04_to_hi02_hole
rumor = base_0_rank, mission_end, 2, 133204
rumor = base_0_rank, mission_end, 3, 133205
rumor = base_0_rank, mission_end, 3, 133206
rumor = base_0_rank, mission_end, 3, 134319
rumor = base_0_rank, mission_end, 3, 134313
rumor = base_0_rank, mission_end, 3, 134314
know = 251630, 252714, 50000, 2
knowdb = ew04_to_hi02_hole

[GF_NPC
nickname = ew0401_bounty_002_f
body = pl_female2_journeyman_body
head = ku_newscaster_head_gen
lefthand = benchmark_female_hand_left
righthand = benchmark_female_hand_right
individual_name = 220993
affiliation = gd_bh_grp
voice = rvp516
misn = DestroyMission, 38.983860, 53.365002
room = bar
bribe = gd_z_grp, 10000, 16102
bribe = gd_bh_grp, 10000, 16101
rumor = base_0_rank, mission_end, 2, 133201
rumorknowdb = ew04_to_ew03_hole
rumor = base_0_rank, mission_end, 2, 133202
rumor = base_0_rank, mission_end, 3, 133203
rumorknowdb = ew04_to_hi02_hole
rumor = base_0_rank, mission_end, 2, 133204
rumor = base_0_rank, mission_end, 3, 133205
rumor = base_0_rank, mission_end, 3, 133206
rumor = base_0_rank, mission_end, 3, 134319
rumor = base_0_rank, mission_end, 3, 134319
accessory = prop_neuralnet_F_up
---------------------------------------------------------
Now please tell me what did i do wrong.

Between this:

faction = fc_c_grp
weight = 30

And this:

npc = ew0401_corsairs_001_f

You need something like this:

offers_missions = true
mission_type = DestroyMission, 0, 0.112387, 30

You can fudge around with the numbers a bit in order to get the correct difficulty levels.

MK

Nothing changes
Can you make a text that I will put in mbases.ini file so that it will work pls?
And for max money on freeport 9 please add 300.000 not more.

Hmmm... possibly...

In the system file itself (ew04.ini), you should find many different zones that have this line (or something similar) in them:

encounter = area_bh_assault, 16, 0.4

Change that 16 to, say, 18, then see if that works (in case you are wondering, that number determines how 'tough' the enemies you encounter are).

MK