The guys are 100% correct that there are jobs that just can't get done without certain power tools . take the drill press , for instance . If your going to be drilling holes in a universal engine mount , those holes are going to need to be perfectly straight through the material or the mount will be weakened . Sure , a hand held power drill would drill through the mount but would the hole be straight ? How about the bench grinder , if your working with anything stronger than wood and need to take a lil shave off so it fits , a bench grinder can save the day . It's plenty useful for other things as well , sharpening lawnmower blades and such .
I guess the real question here is ; Do you do the kinds of work that would require these tools ? Have you been working on things lately and said "gee , a drill press (or bench grinder) sure would be handy right about now" ? If you think your going to be doing the kinds of jobs that require these or any other tools on a regular basis , it's far better to own them rather than suffer the consequences of holes not drilled straight or hours of work with a file that could be minutes with the bench grinder .
And as a final thought , nothing says "Har Har Har , MORE POWER !!!" in that Tim Allen kinda way better than a well stocked home based model airplane factory