First, welcome to the forum. Your question is a real conundrum to me. My guess is you want to find an inexpensive roller locked clone? To me an inexpensive roller locked gun is an oxymoron. Sadly, the Coharie Arms ship has sailed. My understanding is there are no more CA guns being built. I don't think they have any inventory left. You can try calling (480) 30-5652 to ask. Todd has a new company called Bellator Armaments. My understanding is they are currently only producing a K gun. Another Todd company is Black Market Parts. They have some barreled upper products at
MP5 Receivers, Flats, Barreled Uppers if you want to see them. At least on the page for the full sized barreled uppers
Barreled Upper FS (BMP5-147) you could add your name to a waiting list, but there is no full sized barreled uppers in stock.
So my question to you is, how patient are you? This question has a couple of levels to it. You can search the gun boards for a CA94. Beyond the couple boards you have listed, I'd also search right here at hk pro, ar15.com, subguns.com, sturmgewehr.com, and uzitalk.com, which all have a section a CA94 might pop up for sale. Once you find a used full size CA94, it might or might not run. There are also degrees of reliability. Would one or two FTE per mag be acceptable? In the used CA94 you find, unless someone has done some "modifying" of the gun, there should be a lifetime warranty. Any modifications should be disclosed before you send the funds and FFL copy. Sending the CA94 to the mother ship, might or might not help. There are pages and pages of threads here on DIY "make your Todd built roller locked gun run" threads here. The search function can be your friend. There are several very competent smiths associated with this board that can diagnose whatever problem the gun might have and get it to run. Of course a smith's time and replacement parts are valuable and will cost you more money. Personally I've had function issues with the original MIMS bolts that came with my guns. YMMV.
The other end of the spectrum is a custom build. That can be done fairly inexpensively, but again, how patient are you? You might find a deal here, on the parts board, for a trunnion, find a barrel a sturm, buy a cocking tube assembly from BMP, or you might find a deal on a complete HK parts set somewhere else. I managed to find two HK MP5 parts sets for $2,300 shipped. One of them has a Action 3 bolt group. But I had to buy both sets. Another $270 for two CA94 receivers (I had to buy five to get that price) plus $1,100 to have them both built puts my cost at a little over $1,800 each. If you want a rife from a German parts set, you'll need to do some parts swapping because of 922(R). Again the search function is your friend. One of the members here, is having a run of clones with premium US made parts. Check out the thread
http://www.hkpro.com/forum/hk-clone-talk/150081-hk-mp5-clone-buy-special.html for more information.
Your question is about as big, at least to me, as I want to buy a German sports car. Is there someplace else I could buy a German sports car beyond the two car dealers in my town? I'm sure if you had $3,000 in hand, you could have a great quality MP5 clone in your hands by next weekend. How inexpensive and how long before you have a roller locked clone is up to your patience and your wallet. Again, the Coharie Arms ship has sailed. At least for buying a new one from Todd. The good news is you only need to find one (at least to start). I hope this post was helpful. Good luck with your search for an inexpensive roller locked clone.
Scott