I'd park in the garage; that's what we did when we went to see Nutcracker there. You don't know the city, don't know where else there might be to park, don't know how safe it is, and if you pre-buy you are guaranteed a space. That's not a terrible price- you'd pay more than that at any major airport, and think about what people pay for offsite parking for sporting events; here it's $12-$20 dollars!