If you're getting it just for minecraft ( including modpacks ), you can save quite a bit more on the video card. A $150 vid card will be practically asleep playing MC. You could then put that money towards an even better CPU, which will help.
If you do plan to play other games though, a good video card is usually a good investment.
I would not get less than 8 gigs of RAM, as you can quickly use that up these days. ( Especially if you use Chrome for your web browser. Between just modded MC, Chrome with a youtube video at 720p, and windows...I have ran out of memory at 8 gigs. )
Also, if you want future proofing ( so you can just upgrade instead of buying a whole new PC again in a couple years ), you'll want to get a very good/modern motherboard. Currently on the Intel side, this means LGA-2011 V3 socket. This will allows both DDR4 RAM, and a 6 or 8 core CPU. ( Games are already requiring quad core, so if you get quad now...in just a couple of years you will not meet minimum specs. ) Make sure to also get a FULL tower. It will allow the full range of upgrades, including a larger PSU and a large video card. They're big and heavy, but it would really suck to go to upgrade something and find it just doesn't fit.
Another tip: For video cards, the first number is the generation, while the numbers after that tell you how powerful the card is within the generation. You do have to be a little careful each time they rearrange their generation numbering though. ( IE: An Nvidia 280 is better than an 8800 because the 200 series is after the 9000 series. ) This means the later numbers tend to be more important than the first numbers. There are some exceptions, such as when new direct X version come out, or if you're talking a bigger difference. ( A 960 is still better than a 280. ) For regular gaming, I always recommend x60 or better. For MC/general computing, you can go down to an x40, but lower than that usually has a sharp drop in performance, and very little ( if any ) price difference.
http://www.videocardbenchmark.net/ is a good place to get a rough idea of performance and cost. ( Always assume about a +/- 10% margin of error in benchmarks though. They have a lot of issues, NTM different games will actually perform better or worse with different cards. )