I would value it at exactly what you can sell it for on eBay. The actual price will depend on whether you sell them as a set or individually, whether they work, look clean, have working batteries, whether you're prepared to post or just want someone to collect them, whether you have good feedback etc, etc.
If you just want rid I'd list as a set on an eBay auction (to finish Sunday evening) with good photos, accurate descriptions and delivery. Don't have a reserve (it puts people off), either start the listing at the absolute minimum you'd accept or start at 99p and take a chance - good used tools tend to sell well if listed properly, but I did once get a very nice "dalwt 17v angel dill" for 99p!