It is true that all halves from 2002 on are minted in much smaller quantities than previous halves (around 2-3 million per year per mint), and they are only sold in bags/rolls from the Mint as well as in mint sets (these mint set coins are different and produced with a satin finish and special handling...). The Mint also makes a tidy little profit selling these to collectors, check out their website.
However, I agree with everyone that unless you find them in a roll sealed by the US Mint (this is possible, and I have found some this way and certain years do bring a little premium in this case). They generally do not sell for much of a premium...
With no precious metal to drive their value the only thing that would make them bring money in the market is collector demand, and it's just not there...
There are two parts to the equation for value of a coin: supply and demand. These halves do have a smaller supply due to the relatively low mintages (pre 2002 halves have mintages ranging from 15,000,000 in late 1990s/early 2000s to 300,000,000 in 1970s), but the modern NIFCs don't have much on the demand side. Also, since they don't enter circulation through the normal coin distribution process they are normally all in much better condition, so it's not a problem for a collector to get a nice uncirculated coin for a low price...
So, I think both sides are true: The government minted them NIFC, but they really aren't worth much to sell. Not that different from the 1987P and D halves. Although in top condition you can usually get a buck or two for those.
Long answer to short question
I keep a few that are especially nice of each date/mintmark to fill in our Kennedy half books for me and my daughters, but send the rest back to the wild.
I'm hunting silver, varieties, and errors that will sell in the market for the most part. Other than trying to fill up sets for me and my kids. I have built three Kennedy half sets and two Eisenhower/Anthony sets (had to buy the stuipd 1981 SBAs, but found 1973 Ikes) from CRHing as well as one Jefferson nickle set (only need another 1950 D for the second set). It's pretty fun to do this, but I'm not motivated by profit.
Sorry for the long answer.