Hello, and welcome to the forum;
Your question is not an easy one, since it depends on personal taste and time/money.
The trades usually collect up to six issues, so they are a bit cheaper. And because they are constantly being reprinted, it should not be very hard to get a complete collection of TPBs, whereas it may be close to impossible to find all 150+ issues that are collected therein.
Personally, I like to read longer comic stories in a chronological order, which, starting from zero, would be easier with the trades as well.
So, do not be alarmed by the 22 TPBs to be 1) found, 2) bought and 3) read:
The first should not be too hard. Some TPBs may be temporarily out of print, but as I stated above, they are regularly reprinted.
As for the second point, well, your friends and family might have had problems finding suitable birthday/X-mas presents for you?! Not anymore....
And the third part.... Ahh, you're really in for a treat, and you will come to read and re-read many a story (another reason for the TPB; more convenient than unbagging and rebagging the issues
)
So, after reading this first part, I ask myself why I 've collected
both issues
and TPB (or HCs to be more precise)? Btw, this is a question my wife keeps on asking me....
Well, you don't miss anything essential when collecting TPBs only; but the back covers of most of the DH issues have some really great art work that is not included in the TPBs (lack of space, I believe, since the front covers are collected).
And, you know, as a real fanboy and a completionist....
Anyway, this is just my point of view;
Hoping to be of service here; and enjoy your time in the Dojo.