Nope no cheep alternative thats as good. going to cost I'm afraid.
Your best bet from reading several threads about which one to get Tomei or Jun seem to be best choices
Tomei seem to be the best and preferred by most.
It seems The cheaper one's have a higher failure rate and this is something you don't want to fail. And have a 2nd rebuild on your hands
Another thing to think about is that at high revs an uprated oil pump can suck a standard sump dry very quickly so sump mods may be required in some case's.
There is a also an oil way re stricter you can fit into the top of the block to stop the head filling up with too much oil.
Hope this helps there are a few recent threads on this which are worth reading.
After reading them i would go for the Tomei pump and all supporting mods required for it and be confident my oil pressure and levels are good when I'm out having fun
