For the Dr Gominak's RightSleep protocol and also if you are using OSR/NBMI you'll need to be dosing things very accurately. (It's probably easier to you B vitamin drops for RightSleep but only if you can use drops!)
There are plenty of scales sold as "jeweler's scales" online but very, very few even claim to go down to 1 mg precision (0.001 grams) and those that do tend to be quite expensive (even into the thousands, if you want a lab-grade one!). I'm sure these scales aren't going to be accurate enough for commercial lab use but for dosing supplements they are likely to just fine. Just remember there is a difference between precision (how small of an amount they show) and accuracy (if they are actually weighing the amount they are showing!). Reading reviews of these scales, many people are saying they actually are accurate, unlike others that they've bought elsewhere.
These are the cheapest I can find and they can be bought with a set of calibration weights so you can check them to see how close they actually are.
https://www.ourweigh.co.uk/pocket-mini-scales/on-balance-ck-20-milligram-scale.html
They come with their own calibration weights (built into the scales!) so you can easily calibrate them and you don't need to buy any extra weights.
In use I find them pretty accurate.
If you are in the UK, shipping is easy but they will ship them anywhere in the world, but their shipping is expensive. However they are very happy to let you arrange shipping, which should work out a lot cheaper, albeit it's a bit of messing around!
You'll need to pay for the scales first and since you are doing that for export you won't pay the VAT shown on the site.
Either use the "Need Help" chat button or fill the form here to ask for the below:
https://www.ourweigh.co.uk/contact.html
Paying: Sometimes it seems easier to email credit card details (not that this site asked me to, but others have) but I'd never do that! But you might use a service like https://onetimesecret.com/
Once you've paid:
I use Parcel2Go (use the "Send Internationally" tab not the default "Send UK to UK" tab that first appears):
Make sure to buy "Collection" shipping (a service that collects).
You will need the address and telephone number (from their email) and the export codes for the two items:
Scales:
Commodity Code: 84231090
Made in: China
Weights:
Commodity Code: 90160090
Made in: China