Although I am not familiar with Inventor requirements, I would like to point out that intel cpus tend to perform better than amd cpus of similar specs but you usually get a better deal with the amd cpus.
I have a few links you might want to look at:
http://www.bestbuy.com/site/refurbished-15-6-thinkpad-notebook-8-gb-memory-250-gb-hard-drive/1308514947.p?id=mp1308514947&skuId=1308514947&st=c ategoryid$abcat0502000&cp=1&lp=1
- $549
- core i7 quad core @ 1.6ghz
- nvidia quadro fx880m 1gb gpu
- 8gb ram
- 250gb hdd
- 1920x1080 15.6" screen
http://www.bestbuy.com/site/Samsung-...eci fications
- $449
- core i5 @ 2.6ghz-3.2ghz
- 750gb hdd
- 6 gb ram
- intel 4000 grahics
http://www.bestbuy.com/site/ideapad-p500-touch-15-6-refurbished-touch-screen-laptop-6gb-memory-1tb-hard-drive/2322036.p?id=1219071842859&skuId=2322036&st=catego ryid$abcat0502000&cp=2&lp=18
- $499
- core i5 @2.6ghz-3.2ghz
- 1tb hdd
- 6gb ram
- intel 4000 graphics
- touchscreen
http://www.bestbuy.com/site/refurbished-15-6-aspire-notebook-6-gb-memory-500-gb-hard-drive-and-24-gb-solid-state-drive/1309407651.p?id=mp1309407651&skuId=1309407651&st=c ategoryid$abcat0502000&cp=2&lp=43
- $539
- core i5 1.8ghz
- 500gb hdd + 24gb ssd
- 6gb ram
- intel 4000 graphics
- 1920x1080 15.6" touch screen with a nice hinge
I would probably go with the first 1 on the list above (lenovo w510) if you intend it just for cad because it has a quadro fx880m graphics card. geforce series is more geared towards gaming and quadro is intended for applications like cad. however, if you intend to do some gaming get a laptop with geforce. if you dont mind paying an extra $200 over your budget i would go with the last asus you listed on the google doc.