Good morning Greg,
Don is absolutely correct regarding the capital gains reserve. Be careful though that the sale qualifies for the this reserve. A variety of sales are regulated to a shorter 3 year reserve. There are some catches that typically are not an issue, but occassionally spring up. Provided that you recommend that they discuss the reserve with their accountant, I believe you`ll be on the side of the angels. The reserves do not eliminate the tax as you likely know, but merely spread the tax out over time, often with a heavier push towards the end of the reserve period.
Warm regards...
George