I've always bought inexpensive seeds. They tend to be old stock and irregulars. They're not in the breeders packaging because the breeders have "dis-owned" them to a wholesale dealer. Although the genetics are usually authentic, the germination is SLOW and often fails.
Recently I spent the money for seeds from a few different breeders and bought direct. The seeds crack in 12-18 hrs, seedlings are well formed and look healthy. I didn't buy anything with an outrageous price - but my seeds are fresh and do well, removes a lot of anxiety.
Read a lot of reviews on any seedbanks you may want to try. If you purchase seeds in orig. pack from a good name, even the inexpensive varieties are at least good enough for them to put their name on. Spending a bit more for quality is more than worth it, but there are prices out there that make me raise my eyebrows.