You will need an actual pic or video of the diamond. No way to tell from this especially SI2
Yes, you shouldn't choose any diamond without a photo or video, but never in SI or lower. Ask for a magnified photo or video.
What is the jeweler's price on this stone?
Yes, the price is too high. I did a search on the pricescope diamond search and the prices of a GIA Ex cut I SI2 1.07 cts ranged from $3200-$4800, and I'd say the median price would be around $4200-4300.
Are you saying this exact stone is on JA at $6k? There were none in the search nearly that high.