After discussing it abit here: http://www.steamgifts.com/forum/N7bwK/group-buying/page/31337

Group Buy Tips:

• One person must volunteer to host a group buy. He or she announces this and asks for other people to join the group buy.
• Once a group buy is filled, the host needs to edit his or her posts to reflect that the group is no longer open.
• The people who join a host's group buy will PayPal their portion of the gift pack fee to the host.
• PayPal will charge the host fees for receiving payments unless the person sending payment selects the Gift option when he/she is sending payment. Use discretion when choosing to gift funds. You will not have buyer protection if the host fails to provide the game to you. Still, if the host has positive trade feedback, it's probably safe to trust that person.
• Deleted...
• If you have trouble finding a group buy with open slots, consider hosting a group yourself.
• If you already own a game in a gift pack, you may not be able to host a group buy. Steam doesn't allow it with traditional 4-packs.

Copied from CAG: Steam Group Buy and Gift Requests thread

1. Borderlands Game of The Year

1. NGPriest
2. Taken...
3. Taken...

2.1 Borderlands 2 GamersGate

Blue Coins: 59950 -> 40000 (Approx 32,48€)

Hoster: WarrantOfficer

1. Sean
2. Ptival
3. Nick

4. ---

2.2 Borderlands 2 Amazon

US$34.4

Hoster: elbersame

1. elbersame

2. ---

3. ---

4. ---

3. Left 4 Dead

US$19.99 -> $15.00

Hoster: NGPriest

1. NGPriest
2. [Forgot his name...]

3. ---

4. ---

4. Left 4 Dead 2

US$19.99 -> $15.00

Hoster: NGPriest

1. NGPriest
2. NGPriest's Friend

3. ---

4. ---

6. Awesomenauts GamersGate

Blue Coins: 9990 -> 6880 (Approx 5,80€)

Hoster: halnco

1. halnco
2. Shierzhi

3. ---

6. PAYDAY™ The Heist

$19.99 -> $15.00

Hoster: Dirminxia

1. Dirminxia
2. Taken...
3. Taken...

4. ---

Note from NGPriest:
If you're in Australia, i accept NAB Deposit (or IB Transfer)
If you're in Malaysia, i accept Maybank Deposit
If you're in another country, i accept Paypal?