Katl's keychain company produces keychains that sell for $$1$ each. On january $1,2015,$ the company had inventory of $8,000$ keychains. during $2015,$ the company sold $900,000$ keychains. At the end of the business year on December $31,2015,$ the company's inventory was $9,000.$ What was the value of Karl's total productoon anr inventory investment in $2015?$