I think the burgers at Lush are SO expensive! It's usually 40 kuai (and it doesn't even come with fries on the side?!??!!) If you walk down the street, there's a new burrito place where you can get chipotle-style burritos for just 20 something kuai! Right now, they're even giving out free beer!!! I would start the night at Avocado Tree instead :)
Despite the fact that you're shilling for the place, 20 kuai burritos and free beer sounds pretty appealing...