Thanks for the feedback. I have a pretty good relationship with a tailor so buying a used tux seems like the best route. Don't want my girlfriend to be known as dating the fool who doesn't dress properly.
Next month I'm attending a black tie wedding with my girlfriend and this will be my first black tie wedding. I have four possible options:
1) Wear my black pinstripe suit. This option is the least expensive yet is kinda cheap.
2) Rent a tux. Satisfies black tie requirement but rented tuxes can look kinda crappy.
3) Buy a cheap tux on Ebay. This option isn't expensive but cheap tuxes on Ebay are all polyester.
4) Look for a used tux. ...