Requires professional appraisal.
Up to 500 USD
Recently saw one LNIB that auctioned for $605 on Gunbroker.
300 or so
It depends on the model
Browning never "made" a 45. They sold the SIG with their name on it. Similar to their 380 which was made by Berreta.
100-1000 depeding on specifics
50 dollars
550 USD
That is not a valid Browning model designation.
Never made in Belguim
9x18 is the Makarov cartridge. Browning never made a firearm chambered for it. They did, however, make such a pistol in 9x17 - otherwise known as the .380 Automatic Colt Pistol. It was actually the Beretta 84 'Cheetah', badge engineered and marketed as the Browning BDA 380.