Like mentionend above ,
Focal, Dynaudio,Adam,Fluid Audio are good options 
in the price a bit above 500 bucks.
Wouldn´t recommend to save money bying monitors
having an antelope interface and a machine from Mr. Roseberry.
 
The best interface sounds bad with low budget nonitors.
 

Under $500 >>>  JBL LSR 305's

For a budget under $500/pair, you won't go wrong with Equator D5s.
 
Cheers,
Eddie
 

https://www.sweetwater.com/store/detail/HS8    This is what I'm going to get next.  
 
Little more than $500 but you can also get a pair of the HS5 for $400.  
Still an industry standard the HS8-8 is considered a good replacement for the NSM 10's. 
I think under $500 is limiting I would not compromise on my monitors. 
 

Thanks: good advice. Yea, 500 is low. Let's make it 1000.00 for the pair (which is probably still on the low side, but at my limit currently. I will look into the Yamaha HS8, Hs8, Equator D5, JBL LSR 305's, Focal, Dynaudio,Adam,Fluid Audio. I've somehow gotten  by with my old Alesis Monitor 0nes and Sony 7506 phones because I got to know them and compensated (e.g., limited bass in the monitors and accentuated 5kish phones). I'm ready to get to know "somebody" new.

And what's a great idea is to keep those Alesis one's as a second set for referencing and you get to learn your new set. 
I think $800- $1,000 gets you most anything suitable to a home studio set up, Save your money and buy some room treatment instead. A friend of mine has been building a very high class studio in a basement. We rehearse there and the walls are now treated and wow, even with drums everything is separated and clear. No standing waves etc. I have never played in a basement that sounded that good. Oh and he bought the HS8's that's why I'm sold. He's researches the heck out of everything and all his gear is "dream" gear. He also just bought a Behringer x32. His only mistake is he uses Pro Tools :) But he took a 2 year course in engineering and that's what they teach. I'll have him on Sonar soon enough when he starts to get into midi and VST's. He's still 100% audio so Pro Tools is as good as anything. 

Thanks Cactus...yea, good idea re: Alesis-to -new reference. A friend and pro engineer also mentioned the HS8s. I just looked at them. They are powered. I hadn't considered powered vs not. I suppose it's one less thing to by (stereo amp). Somewhat off-track, but regarding your room-treatment advice. I don't imagine it's rocket science placing the treatment; I wouldn't think I'd need a room analaizer. There's plenty of good common sense suggestions online. However, some report thickness as critical. I suppose auralex or a similar company is where buy.  Thanks again.

For a budget under $500/pair, you won't go wrong with Equator D5s.
+1 on the D5s
 
 

When we talk monitors these day's it's always powered. It is actually getting hard to find appropriate power amps to use in studios. My last search was looking at well over $500 for a passive cooled 100 Watt Amp and only a few choices. I found a used Kenwood KA 76 for $20 so I'm getting by with old tech, but I will be looking at the Powered Yamaha's next round of upgrades. 
Powered is were it's at. 
 
Funny you say Auralex as that's what my friend used. He say's they have all the information on their web site and he just faked it using common sense. 

kawika, try to shop used if you can. People are always upgrading their speakers, and second-hand studio monitors have usually lived a pampered life and are still in good condition. You'll likely be able to get something better within your budget. Mackies, Events, KRKs and Yamahas are very common on the used market. Mackie HR824s, being closed-back, are good for a home studio and can be had for well under $1k for a pair.
 
Don't go to Auralex first. Too expensive. Check out realtraps.com for better prices and far more helpful information.