Wondering how much my xbox live account is worth

I'm not sure if I want to sell my xbox account yet but I'm looking for an estimate of how much its worth. it has:

DOOM II
Castle crashers
Battlefield 1943
Watchmen part 1
Lego star wars the complete saga
castlemiiner z
CoD elite premium
Assasins Creed II
Gears of war 2
Battlefield 3 close quarters
stan lee adventure pack
Gears of war 3 Season pass
halo anniversary pre order birthday skull
all gears 3 beta unlocks
infected omen skin pack
battlefield 3 online pass
battlefield 3 back to karkand
shotguns launch pack for gears 3
halo reach anniversary map pack
halo reach defiant map pack
homefront battle code
all halo 3 map packs
black ops first strike map pack
all call of duty waw map packs
borderlands the underdome
borderlands zombie island
spider man 3 new goblin
GTA the ballad of gay tony'
left 4 dead survival pack
metallica death magnetic album
all gears 1 maps

plus avatar items, themes, etc.
the gamerscore is 7200 and the gamertag is Teletubsy