http://cgi.ebay.com/DC-Audio-12-Level-3-/160456823936?cmd=ViewItem&pt=Car_Subwoofers_Enclosures&hash=item255bf8d480
i would bid on this sub and try and get it now while its still up so lets just estimate around $120 for the sub with a max bid of 95 plus the 25 for shipping. and yes the sub does have a hole in the surround but that is an easy fix so well worth it.
http://www.sonicelectronix.com/item_25328_Planet+Audio+TQ1000M.html
with this amp so that brings the total to about 200 so far.
http://cgi.ebay.com/4-GAUGE-AMP-KIT-2000-WATTS-CAR-AMPLIFIER-INSTALL-POWER-/350372929192?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item5193da9ea8
with this amp kit so now the toatl is 226 and i would just build your own box i can design you one if you want me to(just pm me) and it will probably cost you about $45 to make the box if you go to home depot and get 1 4x8 sheet of 3/4 mdf, wood glue,silicone, and 1.5 inch dry wall screws now that brings your total to $271. the first thing i would do since you have $150 is get the dc level 3 12 sub. the next thing i would do is build the box. then save some money and get the amp kit and lastly get the amp. and this should be a pretty clean budget setup that will work great for a daily!