All just conjecture on my part:
Samsung prices have only gone down so far because of the cuts to pricing on the M4. You gotta remember that there are only a very few NAND memory manufacturers.They make money by either selling the NAND on the open market for open market prices (which fluctuate like crazy) or they use the NAND on their own products (Like SSD's). Currently I'm sure there is a larger profit difference in selling NAND on your own SSD's versus the open market. However, companies don't want price wars to drive their SSD prices down too far or it'll end up making it more profitable to simply sell the raw NAND on the open market, despite it's volatility, and then their whole SSD division investments become a money sink with no where to make money. Neither company probably wants this price war to continually happen to their top-tier products. Look at DRAM memory module makers for the race-to-bottom pricing. Volume and market share don't mean squat if you can't make a profit. The consumer SSD price wars are happening at the moment and while a nice short term thing, is not what any manufacturers want long term.
Price-wars are great for consumers, but lousy for manufacturers profit margins. The holy grails are always big OEM computer maker contracts. That's where the real market share is determined. Not the cut-throat open consumer market. These OEM SSD contracts pretty much excludes any SSD makers who don't also make their own NAND of which there is very few. Why, because if the price of NAND on the open market flips the other way, the SSD manufacturers who make most everything in-house are most stable.
The majority of office workers get to spend 8 hours a day on their clunky typical IT-supplied HP's and Dells with crappy hard drives. A cheap SSD like this would be perfect in new office PC machines. IT departments "demand" name brands at low cost. Ultimate top performance is never a concern, just reliability and good enough performance. Maybe Micron wants a cheap SSD for this market (perhaps re-branded to Del/HP/etc. I personally would rather have my clunky dual core HP work machine upgraded with a cheap SSD like this V4 SATA2 SSD than a brand new quad core with a typical crappy small hard drive. Why? Because like most office PC users I'm never CPU bound at work. Mass storage is always on a server so I don't need tons of local storage space. I just want a responsive machine and an SSD, even a slower one, does more for responsiveness in the office environment than anything else.
There's also the problem when you change generations of NAND. What do you do with all the old stuff like equipment, supplies, etc? Fab changovers to new processes are SUPER expensive. If you can create a product or market segment that can use older slower NAND and stretch out the life of existing NAND fabs, you can make money by simply "saving" more money since these older fabs have already paid for themselves and continued production of older stuff is pure profit. I'm sure that these slower (and hopefully much cheaper) SSD's are using older NAND process technology in them. Sure it's nice to always have the latest and greatest, but there are times when it doesn't make sense to use the latest and greatest, especially if you're feeling out the super cost conscious "normal" joe six-pack consumer, or maybe corporate IT type upgrades.
Arguably, both Samsung 830's and Micron M4 are pretty much top tier SSD's. They use the best NAND they each make and they are both becoming mature products without any more surprise "gotcha's" that new products often have. You could argue benchmarks, but in blind tests, they will pretty much be equal to the "normal" user's experience. Sure the 830 is probably 4-5% faster overall, but it's not something "anyone" is going notice browsing the Internet, working in MSOffice, sending e-mails, Facebook, etc. Making little profit on your top tier product to suit the average cheap person makes no sense when you can sell them something that cost less to make/sell and target your top tier stuff to to the more-discerning buyers.
I think the V4 is Micron's answer to this name brand, cheap-but-fast-enough-to-impress-Joe-Six-Pack market and possibly IT departments, but doesn't cost much to make. They just need to get the pricing in line with performance/cost, which will probably take time. Heck, just look at the name (V4). I'm thinking it's an engine reference. The average person doesn't know crap about their PC, but the terms V4, V6, V8 etc, are easily understood in relative performance by normal people. I'm guessing their will later be a V6, V8, or V12 product. Could be wrong though. It just makes sense from a marketing name perspective.
If you didn't noticed, until the 830's dropped in price to sorta match the M4's, M4's were the one's people were recommending and buying. 4-5% overall performance difference isn't worth $75+ dollars in price difference even to most Anandtech people. Samsung "had" to drop their prices even if their performance was better. They "will" raise their prices when Micron raises theirs again. They didn't drop the prices out of the goodness of their heart. Micron probably only dropped the prices so much because they have no other SSD product on the market to do so until this new V4 came out (although it is apparently not reflected in pricing strategies yet). It's probably better to make a small profit from a lot of lower tier SSD's than it is to make the same small profit from a lot of top-tier SSD's. Just looking at the specs, once the pricing gets in line with market expectations, I would much rather have one of these than any hard drive, especially in my cheap devices like an older laptop.
According to some statistical market share analysis I read for NAND a while back, Samsung was #1, Toshiba was #2, and Micron was #3. With Micron's recent acquisition of Japanes bankrupt memory manufacturer Elpida (spelling?), I believe (although not sure) Micron jumps to #2. One main difference that might appeal to Joe Six-Pack is that Micron is a "US" based company while none of the others are.
Again, all just conjecture on my part.