I'm just using my machine as a baseline. It cost $500 five years ago... at Best Buy. I am assuming if it can meet my current needs for Solidworks then a modern $500 laptop ordered off of Amazon will too. These were the two I had looked at so far:

http://www.amazon.com/dp/B010SBAJDS/ref=cm_sw_su_dp

http://www.amazon.com/dp/B0158XJGJ4/ref=psdc_565108_t2_B010SBAJDS

That first one has integrated graphics but everything I've read says for my purposes it should be OK.

The $450 toshiba has a:

Mobile Intel HD graphics 5500 with a Intel Core i5-5200U Processor, here's as link on a amazon:

http://www.amazon.com/Toshiba-Satellite-C55-C5241-Laptop-Intel/dp/B010SBAJDS

And the $550 toshiba has a:

AMD Radeon R6 Graphics and an AMD A10 8700p processor