Cables for a fledgling system

The retail value of my system is about 7k

(Tyler Ref Monitors, Rogue magnum 66/88, Cal CL15)

my cables are currently all stock/(with the exception of speaker wire which is signalcable)

I've been contemplating upgrading my power cords/interconnects (current wall sockets are standard).
15% would be 900/450 (retail/used)
10% would be 600/300

should I take the leap and toss 300ish on cabling for my system or would that be money better spend in upgrading other components? (My system uses 2 interconnects, 3 power cords, and figure speaker cable is already taken care of with the signalcable gear)

any brands in this price range? or recommendations?
I also have a set of Tyler Acoustic speakers (7U) and have
experimented some with IC's and power cords. Compared to some high end audiophile friends, my system is definitely budget oriented (Mistral LE integrated & Music Hall CD25 modified 1+).
I have been using Granite Audio 555 power cord and was impressed with it's overall balance. Then I bought a Granite Audio 560 and took it over to my friend with a $40,000 system. He borrowed it for a couple days, then sold his $1000 plus cord and bought a Granite Audio 560. The Granite's are both excellent cords and affordable (don't let the list price scare you off, you can get one for about half that).
I think IC's are a little more dependent on your system and need to be matched to it's strength's (ones that won't highlight it's weaknesses). For my (budget) system, the best I have found for the price are the Pure Silver Sound Quartet IC's. Check out the rave reviews on Audio Review.
I just bought a used 1 meter set on Audiogon for about $100
and my system has never sounded better.
I think you need to budget more money. If you have 300-450 to spend get a good interconnects first from your cd to pre, then pre to amps. I would recomend some used Audio- quest like some Python or viper. If you want more forward character then Nordost blue Heaven. New interconnect like Creative Concepts 3.0 would be nice and in budget.
I am a true believer in cable/interconnects that are just above what comes with your components.

Acoustic Zen is a great source of cables that, even new, are affordable. Used, I consider this shop pure nirvana. Once you have begun to upgrade cables, even from monster cables, you will be pleased with your decision..

Here are some sources that are worth the effort. Never underestimate Stu Wein's products. Bang-for-buck, this man rules!

For the best value in used cables, try the classified Audiogon ads. You are already where you need to be.

that being said, has a great inventory of used cables and you are dealing with a very reliable, up-front company.

For the best web page on cables, try good service, great reliability, marvelous variety of offerings. Prompt service. Inexpensive, but certainly not the cheapest.

finally, some of the Audiogon auctions, especially with Z-squared, are just fine.
I'd put the $ into used I/Cs first. As others have mentioned, Acoustic Zen products are excellent and you should be able to get a pair of used AZ Matrix Ref MK1 for about $200 or so. Also try LAT Synchestra, not as big a name or as widely available, but very good band for $. I would go the AC cords last and think Syn Res Master Couplers can probably be had for about $125/each.