In such budget....you can't get better than this mono!
It is what I called "Old School goodness"....Do buy it and upgrade sub later,If less on budget!
BTW,CV Vmax is a hell strong sub....you cannot compare it with entry levels of Pioneer,Kenwood and Sony subs!
Other option is JBL P1222 sub....but If you find any!.....(Will Eat many many subs as a breakfast with just 400 rms)!