If I Buy Seeds..

from someone right now
will they be still good for next year to germinate

depends if the seeds are viable right now. are they green and do they look healthy? as long as you keep them in a cool dry place, they will be fine for a next year grow.

To keep seeds viable, store in a dry, dark, cool place and in dry, airtight containers. Seeds can be kept viable for years by storing them in dry, sealed Mason Jars stored in the lower shelves of the kitchen refrigerator. Remember: modern, frost free refrigerators have a very dry internal atmosphere, so make sure the storage containers are sealed tightly or your seeds could in time dry out.