I realize it would be less costly to learn on a practice set, but if a half-set is already available is it possible to learn on those and simply keep the drones off? I’m thinking the drones won’t interfere or require more air if they’re off. Or is there something here I’m missing?
If a half-set is already available, I guess I just don’t see the point in selling it off in order to get a practice set.
If it’s a decent half-set then **** yeah, go ahead. IMO, “Practice set” is just a term to make those of us without drones feel less lame. And besides, it’s never too early to start working on tuning your drones 
Sure. Depending on the set, you might also remove the drone stock and plug the bag. Then convert between practice set or half set as you see fit.
In my experience those who started on bag and chanter have a harder time adjusting to blowing the drones while playing than those who learned their bag technique by switching on the drones every now and again at an early stage.
I think it’s a good idea to practice your bag technique while getting accustomed to a steady flow of air going through the instrument, too many beginners try get away with releasing pressure at the end of phrases in order to give the bag a quick refill. You won’t get away with that if you have to keep a set of drones going steadily.
Thanks very much for the replies, that was exactly what I wanted to hear.
so…who’s the maker of said half set?
Taking over from the OP a bit (don’t mean to muscle in), I’ve got a half set on order from David Daye. I’m a total newbie (although I read a lot of piping discussions), and I’ve heard a few differing opinions on the topic of whether to learn with drones or not.
I seem to remember reading an interview with Liam O’Flynn who said he didn’t have drones for the first ~5 years he was learning the pipes, and he’s glad he didn’t because it let him focus on his chanter technique. However I also see posts like the one above saying that they can help with bag practice and maintaining a steady airflow… I think I read a post recently saying that drones make it harder to cover up bad technique in general.
Seeing as I will have drones (and I love the sound) my current thoughts for learning are to get used to blowing a steady note with the chanter first and foremost, but once I start to get a bit more comfortable I plan on adding in the drones to my practice sessions once in a while, probably more and more as I get down the track.
Would love to hear more thoughts on the matter!
Liam O’Flynn who said he didn’t have drones for the first ~5 years he was learning the pipes, and he’s glad he didn’t because it let him focus on his chanter technique.
There are ofcourse loads of anecdotes, do they really make a point though. Johnny Doran learned on a full set. It didn’t harm his chanter playing in any way and he is probably the piper who had the most seamless integration of chanter, drone and regulator playing into his music. But what lesson can we learn from these things? Other than different individuals will make the best of their different starting points given a bit of determination.
I heard Paddy Keenan say he thought it didn’t hurt to get a full set as soon as possible because, even if you didn’t use the drones or regs, you could get used to holding everything right. Makes sense to me (not that I have a full set, but hey, maybe someday). I do have drones, and they’ve made practice ever so much more fun. They definitely help with the tuning.
I added drones to my practice set only 6 mos. after starting to learn the pipes. For me, the pros have far outweighed the cons. Drones really add a lot, and as Cathy said, make practicing more fun.
The only down sides I’ve found are that keeping the reeds working can be time-consuming and distracting; and because pipes sound much more interesting with drones on, it becomes easier to forgive yourself for (and ignore) fixable mistakes in your chanter work.
Both of those things are easily fixed with a little self-discipline, critical listening, and most of all by shutting the drones off when you need to. More and more I find myself doing “hard” practicing with drones off (fixing tricky passages, getting new tunes up to speed, etc.), using the prospect of turning them back on as a reward, sort of like withholding dessert until you’ve finished a healthy meal 
Have fun with your half set!
–Mick