Let's be realistic in our advices. I have seen lots of 16 inchers selling or R/appleswap for $1800. And that was 3-4 months ago. I am pretty sure they are even cheaper now.
Why? Because $2039 will get you refurbished MBP 16 from Apple. You can't charge more than that.
When it comes to 15 inch, then obviously it should be priced well below of the 16 inch' price. Why? Because if you ask $1800 for 15 inch, anyone can easily add extra $200 and get the base ref MBP 16 with 512Gb of storage/better everything.
Also comparing Ebay prices is not a good reference point if you are not going to ship it internationally and calculate the fees.
If somebody on Ebay is selling this for $1900 -
1) It doesn't mean seller gets $1900 on hand - you have to deduct big fees from Paypal/Ebay.
2) Price is high, because of the demand from overseas, where MBPs are more expensive.
3) You have to ship it overseas and be prepared to insure shipping and other problems.
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Personally I would pay for your specs around $1500 - $1600. And i believe this is a fair price to ask.