In all seriousness.....if you buy the one way ticket on another airline for a departure on an earlier day, your original airline will basically void your ticket when you don't show up for the outbound portion and chances are you will not be able to use your return ticket,.....I speak from past experience with this.
If you can get a roundtrip ticket 130.00 each way, for the dates you want to travel, I would say do that and then contact your current airline telling them you will not be able to make this trip and they "should" give you a credit (not a refund) to use on a future flight with that airline.
Hope that helps.