Which is better — 22 carat or 24 carat gold for buying?

For investment: 24K (coins, bars, SGB). For jewellery wear: 22K. For diamond-set pieces: 18K. 24K loses ~5 to 8% value in resale as making-charge proportion is minimal. 22K loses 15 to 25% in resale because of higher making charges. SGB and digital gold avoid making-charge loss entirely.