Yeah, some of the guys I used to run our rig with now build soundsystems professionally, however for studio nearfiled monitoring you are playing a different game.
There is less precision involved with soundsystems.
Unless you are an accomplished accoustic engineer there is simply no way you are ever going to build anything worth even pissing in for studio use.
The most important thing to spend your dosh on in the studio is your nearfields. The sound making device.
Save up, buy the best you can for your money, don`t be a cheapskate.
Good monitors will last you for life.
What are your specifications? I`d have thought the ONLY primary specification for a studio monitor is to have the best and most accurate, level sound reproduction possible for your money.