For HDB flats, the option fee must not exceed $1,000. For completed private properties, sellers typically request around 1% of the purchase price (for example, $5,000 if the property costs $500,000). So, if it is a private property of about that value, $5,000 would be in line with common practice. However, if it is an HDB resale flat, $5,000 would exceed the allowable limit of $1,000.
