Vanilla Air

I was trying to book a flight from Sapporo to Narita and I am quite confused with the checked inn luggage charges. I intend to choose the Simple Plan but during booking, it says checked in luggage cost 2000Y. So I presume checked in luggage is chargeable. If I do not choose this option now, can I pay the 2000Y at the airport or the charges will be higher?

What does it mean ~20kg? less than 20kg? Last time I was in Nagaoya, I bought a dress I thought was 3800 Y but at the checkout, it was more and the cashier informed me that the sign said ~3800 so that means the rack of dresses cost start from 3800Y..

Vanilla air is a LCC airline (low cost carrier), the low cost means a reduce in airline cost but everything else is paid individually, if you don't pay for the luggage online, the cost will be higher when at the check in counter, the differences in cost is usually stated online with a chart of cost, and usually it's less than 20KG, at a stated amount, and price goes up every 5KG, upto 35-40KG max, so choose the amount online will be cheaper than at the counter, even the extra 3-4KG makes a differences online vs payment at the counter, food and drinks are also not included in the cost, as well as airport tax, fuel and other additional service.

As for the clothes, some shops has tax including at the stated price, but most don't include tax, and will be added on when you pay for it.

Vanilla Air has three fare types: Inclusive (the expensive one), Simple (the cheap one) and Campaign (for temporary campaigns). Up to 20kg are free only if you select the "Inclusive" fare plan. The website is very misleading about it. It sounds like 20kg are always free.

These types of misleading statements and hidden fees are the downside of using low-cost carriers.

Thanks both for the clarifications.

I have not added up all the costs with baggage, but if you're willing to do a bit more detective work you might save some money by also looking at the fares from Jet Star and Peach.
http://www.jetstar.com/jp/en/home
http://www.flypeach.com/home.aspx