Here's my experience. Easy inexpensive seeds, you can buy anywhere (except perhaps China?) and be satisfied.
Seeds that are rare (likely to be old), known to be difficult to germinate or expensive are problematic. Before buying, try to find out about the seeds and the vendor.
Most times seeds are not expensive, at least not anywhere as expensive as plants can be. So take a chance, have some fun. Many times you'll be disappointed but often you'll get some really nice, interesting plants eventually.
If certain seeds are a strain on your budget, that's the time to really be cautious.
If you follow this advice, then you can order from anywhere with the proper attitude and enjoy yourself.
That goes for Rare Exotic Seeds also.
I hate to see that ;( " I do buy there too this years , on 4 pack of dionea mascipula ( 10-12 Seeeds + ) I got 5 sprouting I though it was me but sound like a big no I did buy there with good result in 2017 , sad thing
I wouldn't class Rare Exotic Seeds as a place to be avoided or blacklisted. They are like many if not most sellers of rare or difficult seeds in that they will have some seed that is not viable. Do your research. If the species is rare or hard to germinate, contact the vendor and make sure it's fresh. If you're not sure, just don't spend too much money.
So when you invite people you dont know and they say they want to buy plants, i say just dont. They will spend your time cleaning up your place and take your time that you could have easily spent with youŕ family and leave your place with a big 0$ purchase.
Just dont do it.
You might try to track down his IP address from any email or forum. How did the contact take place? Do you have any evidence the package was sent/received? Maybe a good idea to have an email from the buyer acknowledging the transaction, payment and all relevant details including some personal details to be used if this kind of dispute comes up.