How about some vintage steel...kidding aside you should be able to get a really nice old steel bike for $1500 if you are patient and hunt around.
I have been commuting on this in Shanghai the last 5 months or so. 30km round trip. RMB500/USD75. It works great and I would not be too upset if it gets stolen, rained on, splattered on, dented or scratched. I paid and extra RMB21/US$3 for the seat replacement.
$1500 will get you a lot of bike...