After 15 years of consuming other peoples' creations I'm starting to think about cooking up my own architectural props for my Poser scenes and filling some exterior scenery gaps I've been trying to fill for all those years.  Can someone recommend free 3D modelling software for cooking up building exteriors including texture mapping?  Preferrably something that can crank out .OBJ or something similarly easily imported into Poser.

I'm not looking for anything in which I can rig articulations and for starters I'll be cooking up concrete atrocities consiting of all flat surfaces and square angles.  I first considered Sketchup but to export models I'd have to pay around $600 for the pro versioj (yack!), at the moment I'm thinking Blender might be the way to go but I really don't know what alternatives are out there except Anim8or and the little time I've spent in Blender in the past when using it as a converter to feed my Poser addiction I found a bit bewildering.

Any suggestions are appreciated, thanks.