Do you know how mortgages and interest rates work?
If not, start learning from independent sources.
Get as much information as possible from the lender, with details of all the fees that apply – including any early repayment charges (yes, you can be charged for paying off your mortgage early!). If the loan comes with any ‘sweeteners’ or other features, make sure you understand them and any potential costs. Understand comparison rates and their limitations.
Aside from the purchase price, the biggest influence on how much your home will eventually cost you is the interest rate. On a $400,000 mortgage at 4% per annum over 25 years with monthly repayments (and ignoring fees), you’ll end up repaying a total of $633,404 of which $233,404 is interest. At an interest rate of 7% that interest bill rises to around $448,135!