those ns10s are for reference, theyre not nearfields and they're good...if you need em. I'm not fond of KRK except for the expose series but they're definitly not budget and to be fair about the whole subject, you're not gonna get any worthy buying for the price you're aiming at. In that case you either save up or get something hi-fi since chances are that you're not in the right monitoring environment either (B&W DM602/603 with a class A amp works very well). The cheapest i can think of that are worthy to place as you nearfields would be stuff like dynaudio bm5a's/bm6a's or adam a7's as they're very good in telling you whats going on in the mix, detailed and accurate. As with all the nearfields, they tend to lack the low end display and all of these nearfields could use a sub (A7 + Sub 8 is very good). Nearfields are not meant to boost or hype, they're not supposed to let you feel how loud and how deep the bass is though they will give you a fair impression. If the case would be so, then you end up with mackie hr which i personaly find to be to excessive, the crossover element in the speaker doesnt translate that well and result is that bass becomes kind of muddy in the low freqs thus damping out bits in the mids (mids are mostly the most critical on any nearfield, thus the usage of the NS10s or auratones for reference). Its safe to say that if a monitor sounds exciting it will fatigue your brain and ears and draws you away from the quality of your mix. Mackie really jumped into this bit and choose to trade the low end boost for accuracy while the dynaudio and adam monitors have focus specificaly on the stereo field and accuracy while giving a sensible display of what the lows are doing in the mix (engineering will say, buy the sub were not going to screw up these specs). Last but not least, Genelec 8030/8040 (8130a/8240a+4050a fed through a AD9200 is the shiznit)which are definitly out of your budget but... this s a good impression of what you can expect when talking about quality nearfields, the rest is really mediocre on which the OEM made a hella lotta money on pretty much selling crap because there is demand...you want nearfields for 300 bucks.. they build them but its a tad bit of shame that they really dont weigh up to REAL nearfields, these budget speakers really destroy that definition of what it takes to actualy be a nearfield monitor.
So go ahead and consume, or save up a bit..its only the most important tool in your setup.