Although the price is not realistic, I think they are original Venetian.
The picture is tricky because the middle bead seems huge, but it is only 20 x 16mm and consistent in size with the one on the Sick sample card and the few we found in a shop in Venice in the 1980s.
We have not seen the tiniest ones size 7 x 5mm like those on that strand, but the Venetian usually would make chevrons in different sizes.
The Chinese have made the same colors sequence but the only samples I have seen so far are really big, even huge.
Unfortunately this color sequence is probably the easiest to duplicate which makes it very difficult to judge from a picture.
This website is however showing great stuff and we have done business lately with them, acquiring outstanding beads for the museum.
JP