6000 Chronometer price

Hi,
First time posting. I’ve found an Italian jeweller offering a NOS 6000 Chronometer with the 2 yr original guarantee & a spare Heuer strap for £785.
The model number is WH5113-K1 & the serial appears as No 81891.
I’ve not seen a serial number written in this way before. Is it correct, and is the price good?
Any help or opinions will be greatly appreciated.
Many Thanks

A quick google shows plenty of others with the same casback markings so no issues there at all.

Price I have no clue myself, but again a quick check online shows pre-loves watches in the €500-600 it seems, although also another advertised on Chrono24 much higher. Check online what they’ve sold for before is your best option, but for NOS and with 2yr warranty doesn’t sound bad.
As it’s NOS then personally market value wouldn’t matter so much if I really liked it, wanted it and in my mind thought the price was fair. £785 on a brand new modern watch, or a a vintage watch that is essentially brand new.....