Help Pricing and validating what datejust this is – Unsure of the dial originality

Looking to purchase a vintage datejust. The seller has this listed for £3200 or $4,293.92.

My concerns are
1. Is it a linen or mossaic dial ?
2. Did the 16013 come in blue linen or mossaic dials ? I know the 1601 did and the 1603 possibly ?
3. Is the price worth the purchase
4. What would a bracelet cost me and what is the reference for it.