I'm in a somewhat similar situation. 2014 Model S 60, green, pretty phenomenal condition. It's currently at the service center for ANOTHER LDU replacement (they've had it since 11/21 and it's been tons of excuses, multiple estimates from the original $6200 to $9200 and all points in between), out of warranty this time of course. When I bought it a couple of years ago the plan was always to sell it in 2024 and replace it with a 2018 or newer P100D or a new Model 3 Performance. Now, this $9k out of pocket expense is consuming the $ I had set aside for the 2024 purchase. But as soon as I get it back I'm selling it pronto. The HV battery seems to be in good shape, but I can't be into this 2014 for $60k. (Original purchase price + everything else).
I don't think that you'll be able to get high 20's. The replacement LDU that I'm having installed in my car is really money lost. I'm basically setting fire to $9k.....I'll never see it again. My hope is to list it for the top of the KBB, and the additional warranty will make it more attractive when cross shopped against a similar car the prospective buyer might be considering. I'm crossing my fingers that the FUSC, jump seats, tech package, etc will do the same. Last I checked the "book" on my car was about $18k. If I get stuck with a HV battery replacement I don't think that I could ask $33k ($18k + 15k HV replacement cost) and get it. Both of our cars are older, no cameras or the features associated with them, etc. We're competing against newer cars when we sell ours.
If your car is in great shape cosmetically, based on what I'm seeing in the used Tesla market, I'd think low 20's would be a reasonable place to start. Maybe even list it for $25k and market the battery, LDU and other replacements and associated warranties, while also pointing out the FUSC and possible $4k tax credit might get it done. The prospective buyer would be getting it for ~ $21k with a new battery, LDU and what not WITH warranty coverage. But I think your setting that $15k HV replacement money on fire JUST like I'm doing with my LDU $. It's way harder for either of us to move an inoperable car though, so it's kinda $ we HAVE to burn unfortunately.
My biggest fear for resale is listing it too high to start with. Inevitably, the longer it sits on the market and the more we reduce the price, the more people will wonder to themselves "what's wrong with THAT one?".
Good luck with it. I for one feel your pain. I'm not in HV replacement land right now, but this $9k hit hurts about as bad as $15k would've.
EDIT: I had $15k in my mind for your HV replacement cost.....it's really $19k. Damn. My fault.