I'm attending a three-day conference at the end of the month and the specified attire is "business." It's local at least, so I don't have to worry about packing, but my business wardrobe is lacking. I've never had to attend a conference dressier than business casual and am unlikely to attend others like this in the near future. Or to ever have a job that requires regular use of a suit.

I have one navy suit, one black ponte sheath dress, and a couple of neutral colored blazers and trousers (but not necessarily the same neutrals).

As far as I can tell, my options are (for day one, two, three):
1) Wear the suit, the dress, the suit again
2) Wear the suit, the dress, and then black trousers with grey blazer
3) Go shopping

What would you do in this scenario?

ETA: I just remembered I own both a skirt and trousers to go with my suit jacket! Clearly I don't wear either very often...