You can also ask the seller for their xpub key and use it to derive a fresh payment address for each individual sale.
I didn't know about xpub key, thanks. But after some researches, it seems that it's not a good idea to share your xpub key, so I can't really ask this from my sellers.
There's 2 risks involved when sharing your xpub key:
1) Whoever has access to the xpub key can track your transactions
2) Whoever has access to the xpub key
and to the private key of one of its derived addresses can derive the private keys of its other addresses as well
(1) is precisely what you want to achieve, (2) should not happen as long as the seller keeps their private keys safe -- apart from very special scenarios where they explicitely export a single private key usually either
all their private keys are safe or
none of them are; regardless of whether they shared the xpub key.
So while you shouldn't share your xpub key with random strangers on the internet, the scenario that you describe would be a typical use case for it.
Alternatively, if you don't feel comfortable with asking sellers for the xpub key, you could also have them send you new addresses in batches. Having them send you e.g. 100 addresses a month would still be less cumbersome than them sending you a new address 3 times a day. Not optimal, yes, but unfortunately as far as non-custodial address generation goes you can't do much better than using the xpub key.