Maybe something like this.
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Xeon E3-1231 V3 3.4GHz Quad-Core Processor ($242.99 @ SuperBiiz)
Motherboard: Gigabyte GA-Z97-HD3 ATX LGA1150 Motherboard ($82.98 @ Newegg)
Video Card: XFX Radeon R9 270X 2GB Double Dissipation Video Card ($132.98 @ Newegg)
Case: Fractal Design Define R4 Blackout ATX Mid Tower Case ($69.99 @ NCIX US)
Power Supply: EVGA 750W 80+ Bronze Certified Semi-Modular ATX Power Supply ($49.99 @ NCIX US)
Total: $578.93
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-08-11 06:33 EDT-0400
The define case is pretty decent, good airflow, quieter than some, comes with a couple of decent fans. Some cheaper cases aren't so cheap when you factor in having to add fans to them, a couple fans can easily run $30-40.
The older chipset likely lacks features, not so much performance but also relies on older outdated bios code which can make for compatibility problems with newer chips. You start getting into well does the bios revision support the cpu I wish to run on a particular b85, multiple revisions exist on store shelves so which one will I actually get. If it's an old one, can I update the bios? Does it support usb bios flashing without a cpu or does it require installing an older compatible cpu to then update the bios just to use the cpu I wanted to in the first place. If I can update it via usb, do I have another pc I can download the bios to and hope the bios flash goes successful. Usually it does, sometimes it doesn't. If the bios flash fails, the motherboard is likely bricked unless it has a dual bios feature. Too many headaches to save a few dollars and a lot of monkeying around to make a modern chip work on outdated tech. A bios upgrade to allow newer chips is great for existing b85 owners who don't have to worry about hunting down an old cpu to make the bios upgrade. It helps extend their existing hardware and make it more forward compatible with newer cpus to extend the longevity of the motherboard. For a new build it's just not practical in my opinion.
I can understand where saving money is always a plus, no one wants to overspend. On the other hand, there's such a thing as cutting corners to the point you get burnt. Not to say this is exactly what would happen, but hypothetically someone gets the cheapest motherboard they can. Component quality may suffer, such as static from audio ports, usb ports burning out, vrms which get overheated under load because they're budget regulators, a person gets their $40-50 board and goes great it only has 2 fan headers. Where am I supposed to plug in my case fans? Or gets an older incompatible bios which either runs the cpu poorly or not at all. Now they have to waste time hunting an old used cpu or buy a 'cheap' older cpu which is going to be at least $40-60. Had someone just spent the extra $20-30 up front they could have avoided all those potential headaches and pc downtime when a new build should have been up and running already.