In my oponion
If you want to save money skip the protein skimmer,I always thought they were a waste of $ for a fish only tank.Or buy a cheaper powerhead type protein skimmer since they will work just fine for a 65 gallon tank.
If I had to decide between buying live rock and a skimmer for a fish only tank,I'd take the live rock because it add looks and natural biological filtration. But people also get by fine without live rock or put the rock in their wet/dry to save "fish room" in the tank.
"a canister filter+Emperor 400" will work fine for a 65gal set up as long as you don't over stock it. Or you could go with a skilter brand filter (built in protein skimmer) and the Emperor.
I'd try checking prices somewhere else on live rock,if your just talking about normal live rock those prices are high! Here it's usually like:
Caribbean base - $1.25 - $2.00
Fiji/Fuji $3 -$4.95
Fiji for $4.25 per pound for 25 lbs with FREE shipping!
or
$4.39 shipped to your door Fiji
Tonga shelf $3.75 - $6.00
Tonga branch $6.00 - 8.50
Marshall Island $4.50 - $6.00
Savi , sauvaugie (however those two are spelled),blue ridge and Barrier reef $8.50-$14.00 they're expensive but rarer then most live rock.
You can also make your own live rock useing bright salt water lights kent rock cure (if they still make it?) and some time,. Theres also a few other ways do a search online and you should find alot of cheap ways to do it.