Many different aspects to "worry" about ....
The core issue for me would be the fact that the new house becomes the home that both of you really want.I think the home side of it is so much more important than the money side (For the right "home" one always seems to have to go above and beyond moneywise to secure.) If it is where you both can see yourselves living for the next 10 to 20 years then it's "the Home" so then go for it.I would give more weight to your partners view on is it the "home".As someone pointed out circumstances do change. Reading all the earlier posts it looks like the money side is "doable" so work out why you can't make up your mind...
Sorry if this is waffle..
Exactly Martinslan. I currently own a house but am looking for a home. i feel this is it. I'm going to go for it.