This laptop is more than powerful enough. It is the quadcore cpu that makes all the difference.
Support for graphics cards within Vegas is sketchy and unpredictable, depending very much on the codec used for rendering. (When I 'upgraded' my desktop graphics card, some render times increased rather than dropped... While that new card showed incredible performance for computer games)
". . . some render times increased rather than dropped."
There was a period of time when people were glorifying hardware assist as a fix for mediocre cpu rendering performance. And it worked in some cases.
With quad and i-class processors now at prices such as you mentioned, that's where you need to throw put your money, and get a graphics card that works. The benefits of gpu rendering diminish inversely with increasing cpu performance.