Cables 101, new student, first question


I have a simple question if I can get it worded correctly. For simplicity, let's say my system has four interconnects in a "stream," all from the same manufacturer, some from the top of the line and some from the bottom. Example: Wireworld's Eclipse 8 line, four different versions, the least expensive starting at $325 and the most expensive starting at $1700. In general, will the system's sound be defined by the weakest (cable) link in the chain, in which case all the more expensive cables are a waste of money? Or will a mix of cables that includes some really high-end ones sound better than a consistent run of the cheaper stuff? 

To put this a different way, if I'm buying a couple new interconnects (again, for simplicity's sake from the same maker), might buying better ones improve the sound or will I not hear a difference until I've replaced them all? (Here's the stream analogy: if I put a dam upstream, the flow in the entire river will be reduced.)  


northman
"I've done a budget system where the total cost was $1200 and I've put a $2k interconnect in that system. So I know what I'm talking about."
Priceless!
This is just my personal experience FWIW.  Adding a better interconnect improves the sound of my system even if there’s a lesser one elsewhere.  But it also matters where you install the cables in your system.  I get the best results by putting the better interconnects closer to the source.  Hope this helps somewhat. 
I agree you have to look at the system as a whole. But you need to start your upgrade somewhere and if the interconnects can be improved, then adding one pair of better cables will certainly be an improvement.


@northman, IME, Cables are the last thing you should do to a system to improve the SQ. Some People view cables as “Jewelery” and buy for looks or bragging rights.. Spend the money on the source, a good preamp/amp and of course speakers. then address the power. after all the big money is spent, Buy cables that match the load and spec you require with good connectors. 
if your system is revealing enough, You can tell if your weak link is a cable..  Money is almost always better spent elsewhere.. Cables matter, but they don’t need to be $$$ to make a nice difference..
IME.