Check current pricing for I5 2500K on Tigerdirect or Newegg. I didn't see sale on them today but if you go with Newegg, which is currently priced at $219.99, u can use NEWCUSTOMER10 coupon to take additional $10 off their price for it.
If you can give your budget figure then it'll help us immensely to give some firm suggestions. You will most probably need a dedicated video card for any sort of gaming (assuming games such as crysis). Depending on the software used, few AMD X6's can actually compete with the 2500k in video editing. But they are roughly priced the same so no savings there. You can save somewhat on the motherboard though.