I'll take em for $20

If I was you, I'd go by E-Bay prices. At least to get an idea.

https://www.ebay.com/itm/NOS-Edco-Br...0/173170694159

https://www.ebay.com/itm/Wheelsmith-...0/272422072683

https://www.ebay.com/itm/Wheelsmith-...g/302224740729

https://www.ebay.com/itm/BMX-MTB-Mou...U/201989436289

I'd price them as new. So, it looks like they are coming in at 10 cents to 20 cents each for the 2.0 (14g) brass nipples. Perhaps take a file to one and make sure it is actually brass.

You're probably best off breaking into bags of 100 to 200 or so. But, then it can take patience to get good prices.

1.8 nipples aren't used quite as much, so they may have the prices depressed a bit.