what is value of late 2015 27" iMac

For a pall park figure, look down towards the bottom of > https://everymac.com/systems/apple/imac/specs/imac-core-i5-3.2-27-inch-aluminum-retina-5k-late-2015-specs.html

Also remember to properly prepare it for resale, as per > https://support.apple.com/en-us/HT201065

We know enough about Macs to understand that used prices vary wildly with location. There is a university town 35 miles from me where Macs are abundant and cheap, yet in our town the used prices are about 30-40 percent hight due to a smaller supply of used Macs.

And these are international forums. Peope from all ove the world ask questions. Used prices in one country can be outrageous yet cheap in another.

When I need to get an idea of used Mac prices, I always look at Craigslist.

Hi Raschella2013,

You can see what Apple values it at here: Apple Trade In - Apple.

Cheers,

Jack

Check online sites like eBay and SellYourMac - they have a larger audience.

I'm selling my 2015 MBP 15" on eBay - way more than what Apple Trade in offers...

We cannot tell you that. Look at Craigslist's and other places.

EDIT: what rkaufmann87 said

We know Macs, however we have no idea what they sell for where you live. We have no idea if you would pay shipping, we have no idea of it's condition (meaning we have never seen it or tested it), we have no idea of the configuration etc. There are simply to many variables for us to hazard a guess which is why you need to figure out what they sell for.

You need to do your own due diligence to determine what they sell for. What your address Mac is worth in your area is likely different than in my area. In other words we have zero idea.