What is the Cheapest Choice for a HSS Flash (Nikon)?

Hi
I'm planning to buy a flash and i need the High-Speed-Sync Ability!
i'm looking for Third Parties for cheaper price!
i found Yongnuo 568EX for Nikon…
and now i want to know is there cheaper one or not?

High speed sync can only be reliably done with Nikon brand speedlights such as the SB600 and higher (SB700, SB800, SB900/910).

And you need a mid-level/advanced DSLR, such as a D90, D7000 or above (entry level D3xxx/D5xxx cameras will not work).

Mid-leve/advancedl DSLRs have a function called "FP High Speed Sync" that allows you to use shutter speeds up to 1/4000th of a second. These cameras instruct the flash unit to fire for a longer duration. The flash output is less in this mode, so your range will be limited.

the YN568 is the only 3rd party high speed option sync flash that I'm aware of that will work with Nikons, so you will not find a cheaper alternative. But I always recommend camera-brand flash units as they are guaranteed to work 100%, and my experience has been that even the best 3rd party flash units (such as Metz) are not 100% compatible.

You get what you pay for…