Hi,

I am about to book a flight from Krabi to Bangkok (08.04, one-way), but the prices are rather high in my opinion. I remember to have paid  1300 / person to Thai Airways in 2019, low-cost airlines were a bit cheaper (ca. 700 baht  + baggage). This week the cheapest airline is Lion Air (1750 baht, 10 kg checked baggage included). Is it a good price for these days?

Could be because it's just before a holiday period, Songkran.  Google flights shows cheaper flights both before and after your date;

Generally domestic flight prices have risen like in the rest of the world.

My next trip to Pattaya will be by car after all the cheap flights during COVID.

 

And as above: Sat 8th April is already part of the Songkran price hike.

I checked Thaismile during April and it ranges from about 1500 to 4300! at peak Songkran dates. 

To be correct. Prices with Thaismile in April for KBV to BKK (Suvarnabhumi) are 1600 to 4080 (April 14th / 15th).

April 8th is 3430.

(final prices incl baggage)

Over the past 4 years  something called inflation has had an impact on  airline fares. Jet fuel  costs have almost doubled during that time, and fuel accounts for 40%+ of the costs of a flight.  Labour costs and air craft parts/service costs have increased.. It is  to be expected that the cost of an airfare would increase. That airfare is still less than what it was 25 years ago.