Owned Soundmagic PL-11,Brainwavz m1(sold) , Sennheiser CX-180(sold).
First of all i have tried PL-11 and i would say EP-630 is better than pl-11 for me atleast , ep630 has better bass whereas pl-11 maybe a little better in mids but lacks in bass compared to ep630 , After 630 i had bought the CX-180 and must say i was might impressed with it used it for around 5-6 months , overall good SQ with prime focus being on bass , then i moved onto Nuforce- NE7M which was better than my CX-180 in bass and overall detailing but vocals were not very forward sounding on NE7M , afterthat i bought a Brainwavz M1 looking at its good reviews but sadly i did not like it much , vocals were forward and detailing was pretty fine but soundstage wise i did not like it much and i would recommend cx-180 over a Brainwavz M1 (some people might kill me for saying this ) , i sold M1 and cx-180 and bought a Brainwavz M3 (superb detailing, ok/good soundstage , just enough bass (would like little more) .
I would recommend you to buy a Nuforce NE7M if you can get a 2nd hand in that range , if you want a new IEM than buy a Sennheiser CX-180 or maybe you might want to give a try for brainwavz Proalpha (1.8-1.9k)
From IEM i have tried i would give following rating Brainwavz M3> Nuforce NE7M > cx180>Brainwavz m1 > EP 630 > PL11
I took the exact opposite approach,upgraded from craps like ep630,Sennheiser CX series straight to IE8 and SM3,followed by a slight downgrade(only pricewise)to IE7(which I love the most)I think it would be better if OP goes up the aural ladder. He can then replace the M1 with M2.
IEMs are bound to die