Hi Tyler
There's no doubt in comparison, London and pretty much the rest of the UK is extremely expensive to other similar countries and cities. Like many of the many people who do come here, once you are earning pounds and spending pounds, things get a little 'easier' to comprehend and manage. Usually, those people moving from the USA already know about this and as has been mentioned by people here, you've got to adjust quickly to that and try to resist the constant comparing with 'back home' prices!
so quick way to fix what yer mum thinks is to tell her about the 'relative' costs and earnings you'll be getting here. Maybe she'll understand a little more then, however, she'll probably come back with the biggest damning response which will be 'well you still probably wont be able to buy your own house for a long time and you'll still have to comprmise more in more areas of your life to live there' ! - unfortunatley, nothing you can really say to that except hope smetime in the future things change in a positive way (not price crashes, stock market collapses etc!)
No doubt economically, whatever happens in the USA sends ripples to all other countries, NYC is a very expensive place to live in the USA, but as this site is about comparing and contrasting and discussing differences, NYC has more value for money to UK people and Londonners than London itself! - waiting for the general UK economy to compensate isn't worth persuing so it's either supplement your income here and/or compromise more!
And don't forget, there's another interest rates rise on the cards before the end of the year and some plucky analysts are saying it could well be as soon as next month and others are even suggesting it'll go higher during 2008..... not good...
Anyway, gotta look on the brightside as much as we can - and an appearance of some sunshine might help us all at least feel a bit better!!
Cheers! DtM! West London & Slough UK!