im a wheel nut so i guess i look at things differently. nothing wrong with a set of cast wheels.
OP, with 114.3 bolt pattern your used wheel options are HUGE! for 1000-1500 you can get a nice set of used wheels. Don't get me wrong, theres nothing wrong with cast wheels. Shoot even HRE has a line of cast wheels.
Just saying you'll be paying at least 1k for those wheels right? you can get a nice set of wheels for that price.
Check out zilvia.net classified for wheels, g35 drivers classifieds, vrwheels, and you can even find deals on craigslist.
Personally I would get a set of 3 piece wheels used (iForged, DPE, Works etc), put a little time refinished/fixing them throw them on the car.