How high are the ceilings? What sort of/size base/case moulding will be used?

Your sample looks rather basic. If you're going for elegance as you say, something like below might be a consideration. Of course, other trims in the space (windows, doorways, baseboards, etc.) need to be considered along with the height of the rooms.

I’d ask your real estate broker before installing any trim. I feel like people generally prefer more contemporary and crown molding is traditional. I moved into a center hall colonial that was decorated by the prior owner around 2002 with crown molding in every room and too much decorative trim around the windows. I would generally prefer without.

Context is key, post up pics as your description does ot help fully.

I can’t believe I failed to include the ceiling height. It’s nine feet. The kitchen and breakfast nook ceiling have six-inch v-groove t&g painted white. Baseboard is about six inches. Oak strip flooring in a very light finish throughout the first floor. We may trim the doorways as seen below (example is from a different house).

We had a local real estate agent look at our house and she concurred with the need for crown molding. That’s only one data point, but she seems to know the market in our part of the county.

We expect to list at around $700K.

I have no clue post picsof the rooms you are planning this for .IMO not all spaces need crown. I usually will advise not to spend huge money for resale the next guy might hate crown . If you ask the realto if it will make a huge difference in the price maybe you would get a better answer than asking for them to agree with you.

Whether you are building a home to sell on spec or modifying an existing home for resale, I'd be cautious about adding costs that you can't recoup at sale. Loading up a home with trim may make it easier to sell, but you may not get the incremental cost back in the sales price. Look at homes in your area with list prices close to your intended list price to see what features they have. Those are your benchmarks.

Please show the baseboards, too. The door, window, baseboard and crown molding should match in style and level of elaboration. One overly fancy or out of scale choice will look out of place.

How old is the house?

12 years

I used to live in northern NJ a long time ago and these days I would not expect much of a premium/luxury finish in a house priced in that range.

Crown molding is relatively easy to add and I don't see it ever being the reason why someone buys or doesn't buy a house.

I would just do a simple cove and not call extra attention to it with ornate details, specially with 9 ft ceilings.

I agree with chispa, crown moulding is not a value added product for a home. And 9' ceiling would not get a 8" crown anywhere really. And we are still judging site unseen as you really still have not given anything for context.

Since I’m not a crown molding fan if I were the buyer I would prefer you not add it. But your potential buyers might like it but I don’t think its a ”deal breaker” not to have.