Offer optional items and upgrades

1 Add optional lines

1. In the estimate, click Add Optional Line Item (or check Optional on a line).
2. Optional lines show an Optional tag and aren't in the total until the client picks them.

Mark items as optional in Products & services to add them as optional every time.

2 What the client sees

1. On the estimate link, the client checks the options they want.
2. The total updates right away, and their choice is saved when they approve.