Personally
Id do a mixture of the two, Firstly, if you have any really well known computer stores nearby Id go consult them about it, to make 100% sure that your new vid card would work
consult them, see what hteir tech says, if the tech isnt' sure or you think you might be getting bogus info, get a second opinion
Secondly, Id check back with best buy , see what their return policy is, see what they think about it and all that, they might deny you straight out of returning it, since it was already used,
Best buy are pricks about returning laptops for a reason, because theres a lot of morons out htere who try and scam them for this kind of stuff, So check with their return department, And see what's up with that
if it is true that a new video card would take precident over the old one, I may just attempt that, But only if you can't return it to bestbuy for a new one,
If best buy were to accept it, it would probably be under the terms you only get as much as its worth in credits, Meaning, if your dream gaming machine costs more than that one you have now, Then, You'll be forking over the cash for the upgraded version
Personally I can't say on any laptop brand, because wlel, Ive never owned one, Or used one, Alienware might not be a bad choice IVe heard great reviews about hteirs, But do your research first
If bestbuy says no, and your vid card thing will work, Id invest in it
just be sure that the guy you're talking to knows what he's saying, as I am well aware of the fact that the US has a growing problems of idiots getting into tech positions and stuff, Just something I heard and have learned....
best options though would be to return it and just fork out a little more for an upgraded top, Or just pu tin the new vid card, I have yet to hear of a case where the vid card has to "get used to" the way its used. So Id definitely be looking at an upgrade