This is the first ocarina I own. I bought it because I felt curious about the instrument.
I have to say that, as of now, I am extremely dissapointed with my purchase. Maybe it is the same with other ocarinas an this is a general ocarina issue, but I find it impossible to play it in tune, it is an extremely tonally unstable instrument.
What happens is that the pitch goes up the stronger you blow, which was expected. What I didn't expect was the amount of variation in the pitch. For example, playing the base note of the instrument (with all holes covered) you can go from B to E, a full fourth in range, depending on how strong you blow.
So, in order to play in tune you need to know the right amount of air pressure required for each note. This required pressure also changes from note to note, so the same air pressure that makes the low C sound too sharp can make the G sound too flat.
So in summary, really frustrating instrument, I deeply regret my purchase. I would not recommend anyone to buy this instrument, definitely not for 48 ? (which seems obscene right now). I don't think it is worth more than 10 ?, but right now I wouldn't even take it as a gift.