Display Home Lease Back

Hello,

I read another person's topic on display home lease back and i'm also in the process of buying one from a national builder with 2 year lease guarantee at 7% plus 8×3 additional terms;

The property is in Melbourne west area, and one of the biggest growth areas for Melbourne;

I currently have a small mortgage on my current home with repayments of about $1200 p/m;

The new property is priced at $495 000 and my current home is valued at around $420 000;

What i want to do is  i stay in the current home and pay as much of the loan as possible, then when the display home lease is up i want to move in and sell this home; 

The idea behind this is that with the sale from the current home and hopefully with the market rebounding in 2 years time i would have made enough money to pay for the mortgage of the display home and be mortgage free or next to nothing;

p.s the display home is of the plan thus i safe thousands in stamp duty, i only pay stamp duty on the land component at settlement;

I would appreciate feedback on this;