get a taxi from Warsaw Airport to the South East area - towards Chelm. Can anybody advise please how much that will cost?
I don't know but Chelm is 200 km from Warsaw. If you travel by train to Lublin you'd be only 60 km away from Chelm (several trains daily leave toward Lublin). That is if you care about money... I'm assuming you do since you ask for price.
Have a good trip.