Попробуйте следующее:
import requests
data = requests.get('https://api.hypixel.net/skyblock/bazaar?key=73ac0a44-4c41-4933-a9ee-b4095be2b6d2').json()
res = [product['sell_summary'][0]['pricePerUnit'] for product in data['products'].values() if product['sell_summary']]
print(res)
Вывод
[4.6, 13.3, 3.1, 66.7, 5.2, 652.6, 1039.6, 2638.9, 105560.6, 9641.0, 1130.5, 2428.0, 345.3, 838.4, 4.3, 476128.5, 4000.6, 3.8, 2005.7, 3.4, 1579.8, 8530.1, 3.9, 2510.4, 932.3, 1903.2, 15.0, 16.6, 23000.3, 7.3, 4422.7, 4.9, 26.7, 10.6, 2356.7, 3.5, 3550.5, 927.4, 22144.9, 11.0, 10.3, 1.7, 3.8, 29.4, 3.0, 595.5, 3.9, 84493.3, 19.1, 1.9, 1266.9, 62904.3, 2226.3, 111750.6, 1753.7, 881.9, 15275.3, 5.9, 667.2, 1.4, 1242.4, 8.7, 8.2, 511.2, 99.3, 785.8, 0.5, 8822.6, 7003.0, 38.2, 13.6, 225.7, 190.7, 1086.1, 1479.1, 236269.6, 1914.4, 63817.0, 207238.8, 1067.1, 421.3, 79499.2, 1.9, 2.8, 81384.8, 360458.7, 13.1, 386.3, 176250.8, 47973.2, 9.1, 17.6, 8.6, 21.1, 1339.3, 98003.3, 2.1, 0.7, 195.8, 22.7, 669.0, 14586.9, 3165.9, 1805.2, 640.1, 47433.5, 5.4, 25891.6, 6.0, 5.4, 591.9, 19435.8, 213667.3, 141335.7, 252100.5, 49.0, 5.0, 20.5, 6776.4, 194.2, 9103.6, 127661.0, 189429.9, 1380.1, 2651.8, 5.7, 152892.4, 473.1, 12.6, 10.4, 35312.0, 95945.5, 1873.9, 497131.4, 232073.2, 1106.2, 6700.7, 5960.9, 369.5, 1689.1, 205200.0, 236353.8, 5.7, 3580.4, 102838.4, 491.9, 4.9, 2639.7, 5108.3, 23.3, 275.1, 2.9, 19293.3, 3704.1, 1100.0, 9.7, 1571.7, 7.8, 175352.9, 391.6, 292445.9, 12.8, 4521.1, 18.6, 24818.1, 6.9, 4498.7, 5.7, 7.4, 37421.6, 642.8, 171720.1, 471.9, 1014.4, 13.9, 3070.3, 14.0, 16.7, 9.8, 785.3, 633.6, 8.1, 718454.0, 22.0, 1270.5, 164062.4, 16.8, 232260.1, 550.2, 57.8, 1750.4, 2800.7, 541161.8, 9.6, 100743.6, 6004.7, 1253.1]