For us, we looked into the cookie cutter floor plans and there was one that we really liked. Some of the things I wanted was the finished basement, 2nd floor laundry, large master bedroom, open kitchen floor plan, three car (in our case tandem) garage so I could turn one section into a wood shop. The developer gave us a morning room free and finished the basement for free. That little perk saved us about 30K. We were able to choose custom adds as well that made the cookie cutter floor plan unique to us. I'm sure there are a couple out there exactly like ours, but maybe not. I added a service door from the back tandem garage to the back yard for ease of moving stuff in and out if the front garage was used for parking, and also for dog entrance during rainy/muddy type days. (still working out the details on that plan)
We were also able to choose our cabinets, countertops, carpet, flooring, etc, and it made the home "ours". We met with a security company that added some features to the house that are just nice to have. Surround sound in the basement for the big screen, internet ports in selected locations for hard wire access to internet. Basically, we have a central hub for electronics. I don't know enough about that stuff to really say how much I will use it, but for the cost, there didn't seem to be any real downside on the resale value. Yeah, you can find houses on the market that are close to what you want and then add projects, but I bet you won't start with 50K equity, unless you put that much down in advance. Not to mention the cost of the projects you need to do to make it right. Building right now when the market for these kinds of houses is strong means you can see nice increase. I could close next friday, turn around and sell it on saturday and I would net about 20K over what my downpayment was.
That's not to say I don't have any projects in mind to do already. I do. I saved several thousand by having them just install a 3X3 deck instead of the standard 12X14 because I know that is a project I want to do myself and personalize. (apparently having a deck is a requirement in our city) There are a few other smaller things that we felt we could do ourselves that we didn't feel the need to overpay for like chair rails, backsplash, and things like that, but those are pretty easy, fairly low dollar projects.
For us, the building process was not a hassle at all. It was actually quite fun and we loved driving by and watching the house go up over the past 7 months. It was fun and exciting and knowing we were with a quality builder just made us feel that much better. I own a house 10 minutes south of where we are building, and have a lease contract signed to rent it out as soon as we move out.
Finally, the biggest reason why I decided to go with new construction was because the last two houses I have bought aftermarket have had issues that made me feel like I inherited problems that the previous owner knowingly covered up. My basic mistrust of home sellers forevermore added to our need to expand to accommodate twins coming in a month was all I needed to make the decision. We found what we wanted and what we liked, and we did it. It is less than a year since we bought our current house, and the developers had no problem getting us into the new construction.