If you want it gone soon, you are looking around the $500-600 mark. Honestly, someone is doing you a favor by taking it out of your house, though I know that sounds unfair. No way would I pay $1500 for used couches, especially 6 years old at that. That's a long time for furniture to sit in someone else's house and then pay that much for it.
We bought two Broyhill reclining couches from a friend 8 years ago and she used them for 6 months, paid over $2k. We paid her what she asked, which was $500. They lasted us a good while but when we moved, we upgraded. We just gave those away...two homes, well loved, we just wanted them gone.
I know it being real leather helps though - is it top grain? We just purchased top grain leather couches in the fall and they cost us more than $3k...so I know it costs a lot for that leather, but it's worth it!