Bryce and View are great landscape programs, easy to learn and fairly inexpensive you can get great results in both building exteriors and interiors alike but if you are looking for a modeler you'll have to look elseware. If you can find a back issue of Digit#46 april it comes with Amapi 5.15 free it is strictly a modeler but not too difficult to learn. as was said before blender is also free but frankly I couldn't make heads or tails of it. Anim8or is not difficult but I've never been able to get the results that Geralday does. though i have found it useful for morph modeling. most of the others are well out of my budget. it really comes down to what you want to do with it.