You don't need to worry about upgrading everything at once when building a home.
Think of things that are necessary that you would need or want right now and the other stuff can come later.

Some things that are good to do at the beginning are some of the larger upgrades that would be a pain to do later. Upgrade to wood floors and granite countertops up front. These are big projects that you may not want to do later. Having them done when you are building your home will be much easier.

If you are thinking that you would like stainless steal appliances in the future, then that is something that is easily done down the road. Just use the ones you already have, or maybe use a lower end appliance to save some money up front. You don't need the top appliances right now, but they will be great to have when you go to sell your home. Plus, they will be good to get in the future because they will extremely increase the value of your home.

If you think that you may want added wall speakers or cable jacks for your home entertainment system, then you will probably want to have the builder put them in now since they can be very difficult to add later. You don't have to have the speakers put in right away though. That can come later, but it is a good idea to have your home pre-wired for it.

Extra cabinets are always something people like to have, but it is not necessary to put in at the beginning. Also changing out fixtures and putting up blinds are also things that you can do yourself after the building process is finished. Plus, you can probably save money by hiring someone else to do all of that for you.

A custom paint job is another thing that can wait for the future. Contractors will usually just paint a basic color throughout your whole house. If that isn't your style, then you can have a professional come and paint is what you would like later. Plus, you can usually find someone who is much cheaper that can do it for you. Then again, paint isn't as expensive as other upgrades, so if you have the budget for it, then feel free to do so.

Just think of the upgrades that would be difficult doing in the future. That is probably a good key in knowing which upgrades you should do now and which ones you should do later. If you think you can find someone else to do specific projects cheaper, then you should wait and have a different person do them for you. Think of ways you can save money now and you will be happier with the outcome. The other things can come later when you are ready to sell.

Upgrades that you should wait on when building a home may be a little different for each person. Just remember that you don't have to upgrade everything at once. Do the necessary things now and wait for the other things for the future. That way you can put money into the important things upfront and then later you will have money for the smaller things.