We only need to do a little surface modelling along with some rough cut and fill calculations, so the cost of Civil3D isn't worth it to us - we wouldn't be using, what, 90% of its capabilities? Can anybody recommend a lightweight program that can create a triangulated surface model from surveyed points (X,Y,Z,description format) along with some basic modification and volume calculations?

I *think* I can do this in-house- already researched the algorithms - but I'm not sure that would be cost effective.