I paid $99.95 for my AIM NiB, and have no complaints. But it isn't the $200+ variety...I'd choose BCM all day long if spending north of $150.
Many of the AIM and PSA phosphate BCGs that can be found for $100 are more than good enough for the most demanding shooters. Just pay attention to the materials used, especially with PSA.
Here's a BCG with a slick, easy to clean finish, non-blingy, the right materials, and affordable: STS Cerakoted M16 $129
. Great product for the price. I have a couple and have built several rifles using them.
I like almost anything BCM. I have a few BCM and PSA rifles, and one DD. I only keep the rifles I truly love...so I believe in those companies. CHF is a worthy upgrade in my opinion.
I probably have a dozen BCGs at the moment (some sitting in plastic). All of mine are either BCM, PSA, DD, AIM, or STS. It's a part that's worth shopping carefully for in a build, and worth keep a spare or two around. It's essentially your AR's 'engine', and you can have a first rate drop-in replacement at the ready for just $100.