I told myself I wasn't going to buy any more plants this year, but a lot of HapaJoe's selection was just too tempting. I bought Duguetia stenantha and annona dioica seeds, and was blown away with what I received. Duguetia seeds are hard to find fresh, but his are the best I've seen, as half the ones I received were already germinated. Annona dioica seeds also have a reputation for being difficult to germinate if they aren't fresh, but all of the seeds I received from him were firm and sank in water, so I trust they're all viable. On top of the quality of the seeds, he also included a couple extras.
While some of Joe's seeds are expensive, you get what you pay for at his shop. If you buy a seed from him, it will almost definitely grow into a plant in my experience.