If you have money to burn, buy everything
if on a budget start with bare minimums.....
Consider your talent levels too
MS3D is about $20 but if you "need models now" get DM1 or 2 instead
DBC - Enhanced is cheap now too.
Some say go with DBPro, but DBC (boxed version) has alot to offer.
DBC has about 1000 models on the CD (not animated or textured)
and a bunch of textures and sound effects.
if You have a bit more money to spend,
get DBPro instead of DBC + DM1.
If you "need models now" don't get MS3D get DM2. Locate free websites
to obtain sound effects and textures. Most sounds can be edited with MS Sound recorder although thats really only good for trimming unwanted stuff from sounds.
If you have even more money or have talent,
Get MS3D and TextureMaker and look for LithUnwrap ?
You'll need these 3 to do pretty good models. There is a free texture
maker in the DBC show case but it lacks the coolness items of TM
For sound effects I recommend checkout Office Depot or other supply house. There are just countless apps for that in all price ranges.
My vavorite is MTV Music Maker for $10. Its old, clunky, poorly documented (if you want to use the advanced features) but has tons of options. And lets not forget the good old tape recorder.... I know recording to a cassete tape is old fashioned but its very portable. Take it to a gun range, free way, Drive way, cunstruction site ......... Even record yourself and then change the octave using MTV MM to discize your voice.