Suggested price for Gibson heavy duty commercial freezer GFU17M4AW2

[Erika]

I know this isn't a repair question, but I have a 20 year old gibson freezer that I want to sell. I can't find any info about this specific freezer online, and don't want to over price or under price the freezer. It works very well, and in good condition other than missing a few of the shelf arms in the door. Any suggestions would be very helpful! 

[Hiroshi]

50 bucks max.