I use this one which is only $17
http://www.amazon.com/American-Weigh-Scales-AMW-SC-2KG-Digital/dp/B001RF3XJ2
I prefer the American Weigh Systems one, $8 cheaper and 2 kg is plenty, even for when I come close to overfilling my chemex.
Not sure you’re going to find someone selling a used scale worth the money... This is a very popular entry level scale that I see a lot of people in coffee using. I’ve had mine for almost 3 years now and I’m really satisfied with it. It’s fairly precise and quick to read weight. 0.1g readings up to 2000g (good for pourovers and weighing portafilter w/ grounds). It’s not water proof but the plastic boxes it comes with help reduce splashing and I have yet to have a problem with it not being waterproof. https://www.amazon.com/American-Weigh-Scales-AMW-SC-2KG-Digital/dp/B001RF3XJ2/ref=sr_1_7?keywords=Aws+scale&qid=1581547112&sr=8-7
Sorry if this is against sub rules but I figured this was good advice...
I use an American Weighs scale and feel it does a great job measuring to the 10th of a gram. Around $20 on Amazon. I've had it for probably 1.5 years and no issues so far.
Edit:. 2 years and going strong. Link: American Weigh Scales SC Series Digital Pocket Weight Scale, Silver, 2000G, 2KG x 0.1 https://www.amazon.com/dp/B001RF3XJ2/ref=cm_sw_r_cp_api_i_dzbvDbMC4D6SZ
I've gone through a couple American Weigh scales - they're cheap and respond reasonably quickly. I haven't had issues with drift, or at least nothing near the Black Mirror. You can also calibrate them with calibration weights if you want to.
FWIW the one I started with lasted ~3 years (although it was about $15 cheaper when I originally got it) and I have this one now which I have no complaints abt (the lid covers the weigh platform and the button/screen pop into the body so they don't get bumped while traveling.)
AWS 2kg. $20.50. Has 0.1g resolution. Mine works great! Its often recommended here by others.
Not good at Reddit links but here's the scale I use: http://www.amazon.com/gp/aw/d/B001RF3XJ2/ref=sr_ph_2?qid=1461107079&sr=sr-2&pi=AC_SX236_SY340_QL65&keywords=scale Really cheap, really easy to use, doesn't break. Although I do keep the plastic over the buttons so as not to get them wet.
https://www.amazon.com/American-Weigh-Scales-AMW-SC-2KG-Digital/dp/B001RF3XJ2
0.01g accuracy for that weight is asking a lot for the price.
I don't actually have experience with that model, I use a Greater Goods 11# scale for big stuff (1 gram resolution) and an AWS 0.01g weed scale for little stuff.
Try a scale like this instead for things in tenths of a gram: https://www.amazon.com/gp/product/B001RF3XJ2/
But if you want accuracy down to 0.005 g (or 5 mg) get something like this: https://www.amazon.com/American-Weigh-GEMINI-20-Portable-MilliGram/dp/B0012TDNAM/