Goldhammer, on those low priced sets, look at the handle, right where the blade attaches.
If you see a sort of "bulge" of what looks like colored rubber right there, that is because it really is rubber.
Those don't hold a blade firmly enough to do precision work if you put the slightest pressure on your knife.
Now, if you want to have a few handles around for "light work", like curling an area of flash off a model, those will work for that,,,,,,but, if you do anything heavier, the blade will move back in that handle.
One thing they do very well is give us a place to chuck "odd" things into blade handles to create our own tools, such as locking tweezers, stir sticks, home made scribers, etc.
I have two sets of the Micro Mark "on sale" large sets of knives from well meaning friends, those are the same thing, just rubber pinched in around the blade as it is tightened.
Rex