i got a cheaper one on ebay. two piece. probably a factory second or after-run. its got all the stamps and crap in it like oem. but it was misformed so bad, took hours of knuckle busting and multiple quick grips to line it up, i wished i would've spent the 1000. looks great now but it was a chore.
I bought mine off eBay, OEM splitter for $600 shipped (BNIB). Had the install done professionally since the videos kind of scared me. The body shop place that I used, they also installed my H-pipe) told me it was really a 2 person job (just the final part where someone holds the splitter in place and the other mounts it). I've seen (and heard) people do this themselves but it doesn't seem to be overly easy.
My car came with that splitter, but I thought it looked cheap, so I bought a carbon fiber one. Took me two and half hours to change it out. I think I counted 54 fasteners. I also added the lower support that is on the Mustang Challenge cars and the struts, like on the Mustang Challenge cars. Both are available from Capladi Racing. They supply the parts to Ford.