OK, I'm new to these and am trying to get smarter and need your help.

I've seen FALs, L1A1s, CETMEs, and I think a couple other designations for this type of rifle.  I also have noticed an extreme spread in the price range.  I think I'd like to pick up one of these in the next year, but have a lot more homework to do before committing fundage.

Anybody care to give a lesson in FAL 101?

FAL's and L1A1's are NOT CETME's..

FAL's are Metric and the original design
L1A1's are Inch versions of the Metric design

meaning, they took the metric measurements and converted them to Inch to mfg them.  There are some variations between the two. some parts are interchangeable between the two, but as a rule, they are not.

The CETME is a different Rifle altogether.
Predecessor to the HK G3's.



FAL INFO HERE:
www.fnfal.com/falfiles/old_index.html


CETME INFO HERE:
cetme.homestead.com/mbr.html

Thanks.  That gets me started in the right direction.  

Here's my suggestion...do research and put your hands on as many different styles of FAL/L1A1 as possible.  Determine what features you like, buy the necessary parts, and build your own.  My first FAL was a DSA STG58.  I've already changed out the furniture, rear sight, and top cover.  Soon I will be replacing the barrel with something more to my liking and I'm considering swapping the lower receiver for an aluminum one.  Essentially, I'll be replacing every major component on the rifle.  I've come to the conclusion it would have been better for me to have built my own...lesson learned.  

Not too long ago I stepped into new territory and built my first AR.  Some parts were a challenge, but in the end it was satisfying and took a lot of the mystery out of it.

I saw an ad for all parts except the receiver (Austrian STG58 FAL) and it said "For replacement parts only."  Are there some strange BATF rules on assembling these, or can I legally order one of these and then get a receiver and put the whole thing together?

hit the FALFiles link above..

FAL files are to the FAL what ARFCOM is to the  AR15.