Finance: When is it a good idea to take out personal loans?

I would say the best thing to do is to start small.  But, even if your income rises, don't live on all of it!  Live only on 80%.  Here's how:

1.  Give 10% away to show gratitude for what you have.  This calms the "greedies" and takes your focus off of yourself.  If you can't give 10% at once, that's okay--just give something.

2.  Save 10% of your income in a savings account.  This calms the fear of running out of money by jumpstarting an emergency fund so you won't have to go into debt if the car breaks down or something comes up.  Again, if you can't save 10%, save something, as every little bit adds up.

The remaining 80% is your money to live on, so learn to stretch a dollar until it screams!  There are several ways to do this on my money blog on MySpace, so if you want, check it out! 

http://www.myspace.com/debtprooflife

It's better to start "living bigger" when you can get to it.

What you are proposing is called living beyond your short-or medium-term means. 

If you start saving now, you will have a solid large down payment for the biggest house you can buy when his salary increases.

However, if you are really set on getting a big house, and you have a good downpayment ready along with a pre-approved mortgage, why not start researching and finding foreclosed houses?  They are going to go for a song in some areas as banks aren't even keeping the titles on some houses, so they can avoid the taxes.