Opinions will always vary ,so here is mine. Keep in mind I haven’t looked at your ad, I am not in the market and I don’t want to ‘nit pick’ a persons car. That tends to happen some times in the for sale forums.
When I was looking for mine, if a car had ‘new paint’ I became exceptionally critical of the body. Honestly I couldn’t tell a good paint job from a bad one, well maybe if it was ‘obvious’ I could. My first question in those cases would be to ask when it was painted. If it was anytime in the last year, honestly, I would walk away. From what I have seen most cars look fantastic that first year they were painted. It is in the subsequent years that the quality, or lack thereof starts to show. In my eyes if it was a quality paint job, it would take either a lot of money or a LOT of labor to do it right. I know everyone is different, but unless the person fell on financial hardship, I cant see why anyone would dump and run so quickly after getting it looking great with a new paint job. Since anyone could tell a hard luck story, I just walked away. (that is just me though every case is different).
The second thing I would look for is the attention to detail on the body. Why would someone put the capital toward a quality paint job only to skimp on the details. I would want excellent condition bumper fillers, head and tail light plastics, and emblems (if present) in excellent condition AND properly placed. It drives me NUTZ when I see emblems on new paint in installed in the WAY wrong locations. Again, it is a petty thing to worry about since they could be easily relocated, but it say to me that details were NOT being paid attention to with the body work. If they weren't doing that, i didnt want to find out what other details were overlooked.
In terms of engine mods, I wanted at least a 2 years of mileage from the last upgrade. Sometimes that isn't always possible, but I didn’t want to buy someone else's Frankenstein. I wanted reliability. Much like the paint, I walked away from any car that was being sold as ‘brand new build’. I couldn’t see why someone would build the engine with quality parts, costing lost of money, only to ditch it once they got it dialed in.
If the car did have significant mods, I wanted documentation of parts, and a reference of who installed it. If it was self-installed, I wanted an engine compartment that was clean, organized and to be free of any leaks. I was looking for attention to detail and signs of a quality technician. It was a red flag to me when someone said they rebuilt the motor, but couldn’t get the valve cover to stop leaking so they just lived with it. I was in the market for a car to maintain, not to repair and sort out. (Everyone is different in what they are shopping for).
I also wanted all factory options to work. Power Windows, locks, wipers etc. The only one I was flexible on was the power radio antenna. The exception to all of the above would be Unless the car was from a reputable Turbo Buick soothsayer. Some of the guys on here flip cars and stand behind their work once they get a car dialed in.
In terms of price, it had to make sense. If a guy said he did the paint for 12k, the engine for 30k, but was selling it for 10k. I walked away. If the guy wanted something outrageous, I didn’t even call on the car. I also refused to buy from a dealer. Most importantly, I have to get teh warm and fuzzies about the owner. I needed to believe he was honest, and that there weren't any inconsistencies in what her was telling me.
The market has dictated that GN’s always command more than an equivalent condition T-Type. People pay more to be blacked out. So the issue may not necessarily be with your car, but rather with what else is out there. If you have a car you want 20k for, check the listings what else is in that range. If they are are cars in that range, how do they compare to yours? Are cars actually selling at that price or are they constantly re-listed? At the end of the day, only you know what you are willing to ‘let your car go for’. If you are patient, and it is priced right and a good car, it will sell. We are coming up to the warmer weather, so this is typically when the market picks up.
Good Luck with your Sale!