As with many questions in real estate; particularly those regarding home prices, the answers are location, location, & location!
Cary and Apex benefit from their close proximity to Research Triangle Park, RDU airport and Interstate 40 & 540. The downside is that you pay a premium for those locations. I worked for a national builder in the past selling new construction homes. We sold the same floor plan in Garner (Eagle Ridge coincidentally) and in Cary - the difference in price? Almost $100k in base price, primarily due to location.
If being near RTP and RDU is not your primary concern, you can certainly find some very good values in the Garner or other areas located a bit further away.
I'd be glad to help you further with any other questions you may have:
919.413.7600 / Schillingd@hpw.com
I look forward to hearing from you.