how much does it cost to install windows
1 A standard sized bay window costs around $2,000 to $4,000 installed. 2  Odd sized or custom designed bay windows could cost $5,000 to $10,000. 3  A basement window costs approximately $100 to $500 installed. 4  A garden window costs an average of $1,000 to $2,000 and some garden windows could cost up to $4,000.