The problem I see with this is that you will need to live in the RV for the entire time. Many places have limits as to how long you can park. Places may also have rules as to the age of the RVs they allow - and non-running RVs is usually the reason for those rules.
So, say you spend $600 on it now and are able to park it for a month. Come next month, that RV MUST be in drivable condition in order to move it to another location.
You also have to be able to get to work each day. Are you planning on doing that each day with the RV? Are you planning on taking public transit? If so, that will limit where you park the RV - further reducing the number of locations that will be doable.
I honestly think you're better off putting the money into a dependable vehicle. With a good working vehicle, you might even be able to get a second job to increase your monthly income.
I think an RV at this point is going to cost you far more than you are going to be able to afford. And, when you reach that realization, you're going to find it very hard to sell it.