أُولَٰئِكَ الَّذِينَ اشْتَرَوُا الْحَيَاةَ الدُّنْيَا بِالْآخِرَةِ ۖ فَلَا يُخَفَّفُ عَنْهُمُ الْعَذَابُ وَلَا هُمْ يُنصَرُونَ
Ulaaa'ikal lazeenash tarawul hayaatad dunyaa bil aakhirati falaa yukhaffafu 'anhumul 'azaabu wa laa hum yunsaroon
These are the ones who have purchased the life of this world at the cost of the hereafter — so their punishment will not be lightened, nor will they be helped.
A commercial verb runs through this whole section, and it surfaces here as purchase. Scripture is sold for a small price a few verses earlier, the price paid for themselves is called wretched a few verses later, and here the world is bought at the cost of what follows it. The passage keeps describing choices as trades, which sets a value on both sides of every one.