Would my system benefit from cable upgrades?

I am one that has a hard time justifying the expenditure of more than 10% of the cost of 2 components on the cables connecting them. 

It is more about the synergy between cables with the components than the price of the cables.  What is it about the sound of your system you are looking to improve?

I do not believe that your combination of speakers/integrated will be revealing enough for you to hear any cable upgrade.  Don't get me wrong, I am a firm believer in cables (I run Tara Labs 'The One' throughout) but your speakers and integrated won't let you hear the full benefit, if any, of a cable upgrade.  I would upgrade the speakers first.  If your budget for cables is $2k - $3k - I'd push it to the $3k and get some good speakers (used on audiogon - more bang for the buck).  Your ML Motion 40s are not high fi at all.  You need to start there.  Once you get good speakers, save up for a good integrated. Your source is definitely decent.  Once you're there, you can go to the Cable Company - they have a library of cables you can borrow and see what sounds best with your system.  Enjoy.  

A better question, what system would not benefit from cable upgrades?

op

i am with @mesch - don’t spend too much on cables, improve your room, your components

your speaker cables and power cable are just fine, totally in line with the quality of your system... as @soix says, if you play with cables to see if you hear a positive change, try a nicer set of interconnects - buy used, under a $150 a pair, read up on the sonic traits of various brands, and adjust according to where sonically you want to take your system (more open treble? smooth out sibilance? more body to voices? and so on...)

as for @ted_denney saying "A better question, what system would not benefit from cable upgrades?"

my answer would be, a relatively nice sounding budget system with quality bottlenecks in room matching and one or more components in the chain - not to say cables wouldn’t benefit, but it is a matter of priority of what to improve first, for greatest sonic benefit

To answer your question yes the cables will make a difference. But a better path would be to sell the motion 40 then add your $2k-$3k to buy a better pair of speakers. Shop the used market.
 

if you’re really itching to upgrade cables you can try and replace your generic interconnects with something like the BlueJeans or the Mogami Gold with whatever is left of your budget. Just my take on it.