Commonly trade you CS:GO, TF2 case keys on steam level
Also possible trade valuable CS:GO , TF2 , DOTA2 ingame items on steam level
If you want raise level - contact me by leaving comment here or on my profile page, I contact with you ASAP

trade ingame items on steam level:
amount of EXP for items depends on item worth

You can ask me how much will worth required level, I will calculate and say you price or you can use this table:

How much will worth level:
LEVEL=PAY_PER_LVL
0 - 10 = 0.2 Key
10 - 20 = 0.4 Key
20 - 30 = 0.6 Key
30 - 40 = 0.8 Key
40 - 50 = 1 Key
50 - 100+ by agreement

Price grows, because badges give 100 XP, and it takes 100 XP to get to the next level if you less than 10 lvl. The amount needed to level up will increase every 10 levels. It means that after Steam Level 10 you'll need 200XP per level, after level 20 you'll need 300XP per level, etc.