Let me know if you would like a referral to a good builder.
it really depends on what's important to you. A new house probably will have newer appliances and mechanicals (Furnace, H2O Heater, etc) but may not be close to anything and may not have any mature trees in the neighborhood. An older (existing) home may be more convenient, have more charm, more mature landscaping but may have older appliances, mechanicals, etc.
Be careful with comparing prices with new construction to existing homes. The list price for new construction homes may not include the landscaping needed such as grass (sod), shrubs, trees, etc. It may also not have a finished basement vs others that may. I would also look at the smaller things such as window treatments (blinds, curtains, etc.). If an existing home already has these and the new home doesn't, adding these basic items can add up to a significant amount.
I hope this helps. It's best if you have a real estate agent to represent you to make sure you're aware of all of these things. Let me know if I can help.
What you will have to way is what you get for your money on the existing home versus new home, and which one will benefit you the most. Don't worry about which one is a good move for future value, instead, decide which one best fits your budget and current/futurre needs.