complicated house rent situation

Ok here we go...

Me and my American wife-to-be are going to be applying for a UK Spousal Visa in the next 5 weeks. I have a house lined up and am going to sign the tenancy agreement in the next week. The lady who owns it is allowing us to pay just £460 a month for 4 months. Then she wants us to be paying £600 a month, which is fine.

However, on just my income alone, we're going to struggle to pay £600 a month and have £100.95 left over each week. Nevertheless, we expect my wife to have a job by then, which will give us more than enough money to live off.

I have worked out a budget sheet in regards to paying £460 a month in rent, which I plan on sending with my wife's application. Do you think I need to include a budget sheet regarding the £600 rent? Even though we have an option (written on the tenancy agreement) to find another place to live if my wife hasn't found a job by then.

I hope this isn't too complicated and someone can shed some light on my situation.

Thanks

Make your budget for the £460 rent.  No one knows what your situation will be like in four months' time, there's no sense in borrowing trouble.  The application is only concerned with your situation at the moment, many people apply based on arrangements that are intended to be temporary.