I was brain dumping at a friend on the most inexpensive ways to join the Legions, be it 501st Legion or Rebel Legion, and I thought, wait, I should save this for later. Here goes. :)
Terminology & background notes:
* The CRL is the Costume Reference Library, which is what costumes are judged against. Note that it's not the costume that's approved, it's the costume on the person that's approved - the costume has to be proportional on you.
* The CRLs are updated as the fans get better access to source material and as technology gets better. What was approved 5 years ago may not be approved today.
* Caveat emptor! Lots of stuff that's sold won't be approved. Look for claims that stuff is 501st or Rebel Legion approved, and then investigate further if that's actually true or if they're just blowing smoke.
* Do research before spending. Ask many questions. I've heard stories of people spending lots of money, only to find out that their stuff is not even close, so they get super frustrated and give up. Nobody wants that to happen.
501st Legion
The cheapest is probably the Imperial Bridge Crew. CRL:
http://databank.501st.com/databank/Costuming:IC_imperial_bridge_crew The nice thing about this costume is that it's also the basis of the TIE Reserve Pilot
http://databank.501st.com/databank/Costuming:TI_reserve_pilot which then expands into the TIE pilot
http://databank.501st.com/databank/Costuming:TI_TIE_Pilot_ANH (the ROTJ version is slightly different, of course).
The correct answer to "where can I buy some of this stuff?" is "ask the Detachment forums". Costumes are grouped into detachments, and you can ask around for the latest info on vendors. This is where caveat emptor really enters: sometimes vendors will stop doing a product, or their quality will fall off, or something.
To give a ballpark, here's my understanding of research I did months ago:
* hat ($64) from
sewing jenny* flightsuit ($120) + belt ($60) from
wampa wear* jackboots are on your own - this is where women often have a much easier time than men, given that boots are more commonly made in women's sizes.
So call it $250 plus boots as a baseline.
Edit: oh right, cosplaysky.com has been working with the 501st to update their stuff to be CRL approved, and they're really driving prices down. See? Research. Do it. :) Hats for $18 from them.
Rebel Legion
I'm not actually sure, but I suspect a generic Jedi may be the cheapest route. Certainly a fun route; it's possible that a Rebel Fleet Trooper is cheaper, but their helmets may cost quite a bit.
CRL:
http://www.rebellegion.com/jedi-costume-standards-generic/ I got most of my costume from
Khloes, an etsy shop. $145.
Belt, I made on my own; if you buy a belt + 2 pouches, I'd guess that might be $80.
Boots, again, on your own.
You need 3 of 4 extras; I went for food capsules ($20) instead of a robe, because robes are never cheap.
Lightsaber, figure $100 for a cheap one from Ultrasabers. (If you want sound, add $100; if you want a cooool looking saber, that's more like $150 base. An all-up saber is easily $450.)
So call it $345 plus boots.
If you're willing to sew and/or make your own belt, you can probably make the costume for $60 and the belt + pouches for $30. Not surprisingly, a lot of people go this route. (You can also 3D print the food capsules for $9, but they break easily, so I found it wasn't worth recommending.)
All this is worthless if you don't like people in your local Garrison & Base. (501st chapters are called Garrisons; Rebel Legion chapters are called Bases.) So before you do anything, find out where your groups are and signup to wrangle a few events and meet people. Wranglers are like theatre techs - just as the on-stage people can't look good without help, so the Legions depend on their wranglers. Wrangling should be free and a very easy way to figure out "hey, do I want to spend my time with these people?".
To find your local garrison, go to
http://501st.com/maps/index.php To find your local base, go to
http://newsite.rebellegion.com/baseoutpost-location/ In closing, as they always say: may the Force be with you. :)