I can't speak for outside the U.S., but I've been watching Ebay U.S. almost every day for at least a year. For the Uniphase era of Beovox loudspeakers, every tenth pair or so will have the matching stands. Those pairs which do have the stands sell for more than double what those which don't.
You don't mention stands, so I assume you don't have them. As has been mentioned, appearance will be key in fetching a good price. If they were mint, I think you might be able to get $100 without stands. Sunlight fading of the finish, a water stain on the top (it's amazing how many people think potted plants belong on loudspeakers), scratches on the bottom, snags in the grill/fret fabric - any of these will push the price toward the $50 range.
For comparison purposes, here are some Ebay and Craigslist purchases I have made (none had stands) in the past year or so:
M70s no grills/frets, poor finish: $50
M70s, good finish: $100
S45-2s, very good finish: $90
S40s, very good finish, but needed woofer refoam: $40
Current primary listening: SMMC20EN -> BG4002 -> BM4000 -> Beovox M70