Layered tips can offer much greater consistency. Your tip is arguably the most important aspect of your cue since it is what contacts the cue ball. Go cheap here, and it could be detrimental. As others have stated, the cheaper tips can be fine, but quality can also be very inconsistent.
Chalks are another matter, most chalks are just fine from a performance standpoint, as long as you use them consistently. I do like the new Taom chalk for how clean it is. The main difference for me is cleanliness. I like a chalk that is somewhat abrasive as well, it saves you having to scuff your tip.
I get a kick out of people that cry about spending a little extra for tips or chalk, like it offends them somehow.