Duplex - new construction

[Joy Fuchs]

Any advice on building a duplex in today's market. Mostly interested in modular v. Traditional building advice. It's a small lot in Buncombe county, NC, in a hot area just outside Asheville with city water and sewer. Maximum area for build, with all set backs and regs. met is 30x36. Very interested in price per sf for this area and any pitfalls to be avoided if we go modular

Thanks in advance for help-