Can’t help with the second hand but but if nothing comes up I bought myself one of these: https://www.currys.co.uk/products/logik-lflss23-laptop-stand-silver-10239802.html for exactly the same purpose. Didn’t expect much but was pleasantly surprised. Holds a 13” Dell just fine, wouldn’t want to use it whilst typing on the laptop keyboard itself (not super rigid) but to get some extra height which an external keyboard and mouse it does all it needs to. Plus side for small footprint!
Can’t help with the second hand but but if nothing comes up I bought myself one of these: https://www.currys.co.uk/products/logik-lflss23-laptop-stand-silver-10239802.html for exactly the same purpose. Didn’t expect much but was pleasantly surprised. Holds a 13” Dell just fine, wouldn’t want to use it whilst typing on the laptop keyboard itself (not super rigid) but to get some extra height which an external keyboard and mouse it does all it needs to. Plus side for small footprint!