I have to agree with the Canuck that the OP prolly bit off more than he could chew.
skimmers can be made and actually have to be for setups this size they aren't actually as complex as they seem. guesitmate for one made using a 5000gph pump and 2 55g barrels, pvc, fittings, and small air compressor, would come to 450$
some ideas below
http://saltaquarium.about.com/od/diyskimmerplans/DIY_Protein_Skimmer_Plans.htm
the salt is much cheaper than quoted as well if you shop around and find local dealers that aren't chains. hence my quoted 15$ per 150gal tub. That's from a local dealer and yes it's marine salt. total system would be 2600g so you'd need 260$ worth to start
pumps are cheap, dirt cheap compared to everything else. my 6600gph anjon monsoon pump cost me 150$, so I'd say 3 would be plenty of flow.
add 300$ in piping, fittings, and glue
ad another 100$ for an algae scrubber
live sand can be picked up locally for .25 cents a lb. So put that at 600$ at least.
live rock can be picked up for 1$ a lb (it will not be cycled that will greatly add to the setup time) here's the trouble, I woudn't go any less an 1lb per gallon including the filter area so this is the high one at 2600$
filter, intex 8' pool 69$, 15x15' 45mil epdm liner 70$, 3 55g barrels for filter media (one per pump) 60$ for all three. filter media, maybe 100$ max? bioballs are a waste, brushes are cheaper mesh filter media is like 10cents per square foot and you can always improvise with pea gravel and etc.
then you're looking at lighting if you go t8's or t5 prolly 400$
so my diy (in place of buy it all retail and bend over) guestimate is 5459$ initial setup cost without fish
1000$ a year in upkeep.
well out of the OP's price range I'm gathering.
edit: re-read the canucks post and noticed the only thing that he ahd that much more expensive than my above quote was the skimmer. lol Post edited to match also pump semantics might be off, might need 6 to get the water from the pond to the filter pond and back, add 450$ lol now 6grand.