Complex sentence: He turned up to the vault auctions in the finale episodes of series three and was introduced as a new attendant at the auctions, although he has been in operation less than 18 months, Calvin was able to spend a substantial amount of money.
Split into simpler sentences: He turned up to the vault auctions in the finale episodes of series three and was introduced as a new attendant at the auctions. Although he has been in operation less than 18 months, Calvin was able to spend a substantial amount of money.