Since your on a time limit, find out what the JAB sale is and if its 50% off for only one item, just go with them.
Otherwise, try and find a Rack or Last Call and buy a navy/charcoal suit that fits you the best.
There are also thrift store options.
Honestly though, since your on a time limit, buy the suit that fits you the best and doesn't break your bank. You'll probably end up donating the suit sooner rather than later if you spend enough time on these forums, but if...