If the price of a tiny packet of seeds disgruntles you, pass it by and collect your own seeds for free. Not only is the price as right as it can be, it's also an interesting activity and an easy way to replicate a favorite or heirloom plant. If you have access to a healthy Dianthus caryophyllus, more commonly known as a carnation, it's a great candidate for a late summer harvest and you'll have fresh seeds to plant the following spring.
Leave a few healthy Dianthus caryophyllus blooms on the plants until they wither and die. Tie a colorful piece of yarn or string to the selected blooms, so they will be easier to spot when you return to harvest their seeds.
Hold the spent blooms over a large paper sack, one at a time, rolling each bloom gently between your fingers. The seeds, which are small, black and round, will fall into the bag. If you collect seeds from blooms of different colors, use separate, labeled sacks for each color.
Put the paper sack in a warm, dry place out of the wind and shake the bag every day. When the seeds are completely dry, lay them on a flat surface such as a cookie sheet and remove large leaves, petals and other debris. Don't worry about leaving small bits mixed in with the seeds.
Store the dry Dianthus caryophyllus seeds in a regular white paper envelope (or envelopes, if you harvested more than one color) and label it. Store the envelope in a cool, dry place until spring.