As an example of how utterly doable those dpr benchmarks really are, here's a dragonborn dark pact warlock someone (not me) on the WotC boards threw together that does 65 dpr by level 20 using eldritch blast. I repeat: a frikkin
warlock could clear the dpr benchmark for level 30 by the time they hit level 20. A ranger or sorcerer could do far better than this in their sleep.
Level 20 Dragonborn (frost) Dark pact warlock/ Dark Reckoner
17/15/13/10/10/8 starting array
24 Cha, 22 str, 14 dex, 11 con, 11 int, 9 wisdom
The paragon path only adds 1d6 on your Curse damage, otherwise this build also works with Fey pact
I think that you could easily take rogue MC and go Daggermaster for a nice critrate, but I won't.
Feats:
Arcane implement proficiency (Light blade)
Dual implement caster
Curse' of Io's blood: 1+Str mod damage when bloodied
Implement expertise (Rod) +2 att
Draconic spellcaster +2 attack bonus to frost
Arcane admixture (frost, eldritch blast)
called shot +5
Winter touched
Lasting frost
Nimble blade
Dragonborn frenzy
Weapon focus (dagger)
Empowering shadows
Items: level 21 item: Ankhmon's bracers
level 20 item:+4 subtle dagger
lvl 19: +4 subtle dagger
125,000 gp
gloves of ice 9000
Shadow warlock armor 20, 25000gp or 5000gp
Siberis shard of the mage (paragon)
Eldritch blast (Charisma)
To hit 10(lvl)+7(Cha)+4(main implemement)+2 expertise+2 draconic caster+2 CA+1 prime shot+1 (when bloodied)+1 nimble blade: +30 to hit
10% miss chance against 32 Reflex
Damage:
Damage: 5.5 eldritch blast+7 (cha)+7 (curse)+5.5 (ankhmons bracers)+5 called shot +4 main hand implement+4 offhand implement (DiS)+ 4 subtle property (main) +4 subtle property (offhand) + 5 (lasting frost) +2 (cloves of ice) + 7 (curse of Io's blood) +2 weapon focus +2 dragonborn frenzy +3 Siberys shard + 3.5 (dark reckoner PP)+ 1 empowering shadows= 71,5 Average damage
Critical: 102 damage
Dpr: 65.88