Can I ski in non waterproof normal clothes with enough base layers?

I’m at Breckenridge for a conference and had no intention of skiing or have ever skied before. But I’m seeing all these skiers having fun and want to take a half day lessons. I got quoted at $380 for ski rentals, 2.5 hr lesson and lift ticket. First question is that worth it or the usual price?

The second problem I have is that I have no ski clothes and I back-packed to the conference so I don’t want to buy ski clothes. Rentals are like an hour away. Can I just go ski w/ my base layer, chino pants and a puffer jacket?

Edit: Thanks everyone for your advice. At the conference so can’t reply much, but i appreciate and will look into getting at least waterproof pants