Okay, so we spoiled ourselves a little by booking a one hour flight instead of taking a 12 hour bus. It turns out, it costs roughly the same price to bus as it is to fly. So, why not? However, we soon realized that the cost of getting to the airport makes it pricier to fly.
Where did we book from?
We used Vietnam Airlines to find and buy the flight tickets. It ended up costing us around $25 USD after taxes. There's no extra fee for checked-in baggage, but there's a weight allowance of 30 kilograms. For your carry-on, there's a weight allowance of seven kilograms.
Not too shabby eh?
How to get to the airport?
So this is what messed us up. Due to limited options, we booked the flight leaving at 6 a.m. The only transportation leaving that early is taxi, which makes sense. We ended up booking through our hotel, and they charged us 500,000 dong claiming that taxis double their prices in the middle of the night. Given that we didn't have too many options left, we forked over the money.
Were we ripped off? Most likely. So, try to be careful of that.
Other Options:
1) Public Transit
You can take the number 17 bus which connects from the city centre to Noi Bai Airport. It only runs from 7 a.m - 7 p.m. Ask your hostel/hotel to make sure, so you don't get ripped off with pricing.
2) Mini Bus
There's a shuttle bus that runs from 5 a.m. - 6:30 p.m that costs around 20,000 - 30,000 dong. It departs from the Vietnam Airlines office southwest of the lake.