I assume you are talking about the fixed blade version, as the folding version is the 4018F.
In excellent condition, with the original sheath, box and paperwork I estimate you could get $150 - $200 for it. In used/abused condition with no sheath or box I estimate you could get about $60 for it. That's the high and the low, depending on what condition yours is hopefully you can estimate the value.
The USA made Browning Sportsman's Knives from the 70's and 80's have never been ultra collectible, however if you find the right buyer you can do pretty well, as they do have some devoted adherents because they are so nice. The 4018 fixed blade is one of the higher demand models, so if yours is excellent and complete, and you are not in a hurry to sell it, you might be able to get around $200 for it.
I recently put a couple of the folding version (not as rare) up for sale for $75 apiece and they sold in seconds. These were xint cond with original box, papers, etc. I probably should have priced them around $100 or even a little more.
Sorry for the TMI, hope this helps.
1 2 7 14 41 49 82 98 287 574 2009 4018.
Days of Our Lives - 1965 1-4018 was released on: USA: 14 September 1981
The Bold and the Beautiful - 1987 1-4018 was released on: USA: 7 April 2003
4018 days
Without using a calculator... 4018 !
Project U-F-O- - 1978 Sighting 4018 The Incident on the Cliffs 2-4 was released on: USA: 12 October 1978
1
The phone number of the Mendham Township Library is: 201-543-4018.
The address of the Metamora Branch Library is: 4018 Oak Street, Metamora, 48455 0077
The address of the T And T Enterprises is: 4018 Grapevine St, Houston, TX 77045
11 years can be from 4016 to 4018 days, depending on how many February 29's are included.
4018 days are between Nov. 20th 1999 and Nov. 20 2010.