The 7650k is going to launch at ~$100 which is a great deal for 2M Steamroller + 3CU GCN. Mantle/DX12 should be great on those chips.
$105 is much better pricing that what we normally see from AMD.
However, we also need to take into consideration the following things:
1.) The Athlon x4 860K is cheaper (MSRP is $84 as best I can tell) and with higher base clocks than A8-7650K. Also since the Athlon x4 860K does not have to share its stock cooler with an iGPU, it will be able to make better use of its unlocked multiplier for stock cooler overclocking. We can also be certain Athlon's cpu will not throttle when the dGPU is being used.
2.) In order to make full use of the iGPU for gaming A8-7650K will need the fast clocked dual channel 2 x 4GB DDR3 2400 memory (current price gap between that and 2 x 4 GB DDR3 1600 is $13 on Newegg).
So at this point, we are at $34 price difference when comparing a comparably equipped (2 x 4GB RAM, stock cooler) Athlon x 4 860K to a (2 x 4GB RAM, stock cooler) A8-7650K.
Then after that we still have these additional things to consider:
3.) Athlon x4 860K has the advantage of not needing to use a 2 x 4GB kit. (Many dGPU budget gaming set-ups only have 4GB single channel.)
4.) How much does the A8-7650K cpu throttle under iGPU gaming load using the stock cooler? (Remember that Athlon x4 860K won't throttle and can, in fact, be overclocked with the stock cooler)
For a sneak preview of what I mean, overclock the heck out of one, put in a 290x, and then run the GPGPU benchmarks under AIDA64. Watch it use the iGPU and 290x at the same time . . .
I think that is pretty interesting and I'm glad it can do that, but it is still an extremely niche benefit.