There are a whole bunch of waza that you simply couldn't perform in MJER with a double-edge katana, Kevin. I strongly suggest you not go that route.
My wife uses the Cold Steel O-Katana for tameshigiri, & it cuts really well. Don't know if it's under $200, though.
One funny: we happened to bring her katana to a meeting of the Japanese Sword Society of Hawaii, & two of our most experienced members (they're shinsa!) were very impressed. They told us it's modeled closely after a Bizen Nihonto, & that it was likely the sharpest katana we will ever see.
Ken Goldstein
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Judo Kodansha/MJER Iaido Kodansha/Jodo Oku-iri
Fencing Master/NRA Instructor
"A positive attitude may not solve all your problems, but it'll annoy enough people to be worth the effort."