Kitchens and bathrooms sell homes. Typically with a resale, you can recover a higher percentage of the price of upgrades in kitchens and baths than in other areas of the home. Also, a 4 ft. extension often makes a very big difference in the "feel" of a room - particuarly a great room or eat-in-kitchen. Be careful with the finished basement. I don't believe this is a "must have" and you may be able to finish this space for less money than the builder may charge.
When purchasing new construction (even with a tract builder like Ryan or Heartland), it is wise to be represented by a Buyer's Agent who can act as your advocate and provide advice. The sales staff for these builders are usually wonderful and knowledgable people, but they are representing the best interest of the builder.