By Mimosa Spencer and Dominique Vidalon PARIS (Reuters) -Brushing off higher prices, affluent spenders are continuing to splash out on luxuries including $10,000 handbags, high-end perfumes and premium drinks, trading updates from Birkin bag maker Hermes, Gucci-owner Kering, cosmetics giant L’Oreal and spirits company Pernod Ricard showed on Thursday. Yet with prices set to rise further, analysts are asking how long the boom can last before even the wealthy decide they must tighten their belts. Hermes and Pernod Ricard both said they would continue to raise prices due to higher costs, after be…