We did a poll awhile back and to do a basic costume will run between $1000-$1200. Even using FX lite + MRCE which is your cheapest option, you're typically looking at $1000 when all is said and done. Let's not forget that Hasbro won't work out of the box - you need an upgrade kit too. Same with the MRCE - not acceptable out of the box and needs some tweaks to make it 501st approved. And the soft parts, and glue, clamps, etc. to put it all together.
To do really good costume would run only about $200-$400 more (an AP or TE2 kit for instance is only $200-$300 more than FX). You'd have to really work hard to put $2000 into a set, and at that point we're talking RomFx sound kit, Hyperfirm blaster, etc.