Incheon Airport to Seoul Station by AREX

No more worries. Hakuna Matata..heheh.
Partly.

Now, with the completion of the second phase of AREX from Gimpo Airport straight to Seoul Station, the travel time from Incheon Airport to city center is further reduced by 15~20 minutes. Check out my post - Seoul Subway Fare Calculation By Naver. Previously, you need around 93 minutes to Myeongdong and with a few transfers but now it takes about  72 minutes and only one transfer. ^^
"AREX, spelled A'REX as a brand name, is a South Korean railway line that links Seoul with Gimpo Airport and Incheon International Airport. The extension to Seoul Station opened December 29, 2010." - Source: Wikipedia

I wanna thanks Fraulein for her query, if not I will not realize this important fact.

How to go to Incheon Airport to Jongno-3-ga subway Station?

인천국제공항 - Incheon gukje gonghang - Incheon International Airport

서울역 - Seoul Yeok - Seoul Station

종로3가 - Jongno Sam ga - Jongno 3 ga
 
Duration: 1 hour  14 minutes
Station stops: 11
Distance: 60.9km
T-Money: 3,700 won
Cash: 3,800 won.
 
How much will it be if you take the limousine bus from Incheon Airport to Jongno?
13,000 ~ 14,000 won.
 
Saving: 13,000 ~14,000 - 3,800 =  9,200 ~ 10,200 won (Kaching!!) ^^

Tips:
There are 2 type of AREX services:

From Incheon Airport to Gimpo Airport
Express - 28 minutes
Commuter - 33 minutes

From Incheon Airport to Seoul Station
Express - 43 minutes (run every half an hour) - 13,300 won
Commuter - 53 minutes (run every 6 minutes) - 3,700 won

Comparison with other mode of transportation
Airport Limousine Bus - 70 minutes-10,000~14,000 won
Taxi - 60 minutes - 60,000~70,000 won
Private car - 60 minutes-15,000~16,000 won

Other related articles:
Joongang Daily: Incheon Airport Express