Manga collections are built in runs, and a run with a gap or a mismatch is worth far less than the sum of its volumes.
Where the first money should go
One series, from volume one, in one edition. Reading copies are cheap and they teach you what spine wear and page yellowing look like.
Deciding the edition early matters: standard, deluxe and omnibus are different objects, and a shelf that mixes them is neither a reading set nor a collection.
The expensive beginner mistake
Buying a partial set believing the gaps are cheap. The missing volumes are frequently the expensive ones, and a nearly-complete run can cost more to finish than a complete one cost to buy. What a collection is worth.
The second is buying an unofficial printing without knowing. Ask where it came from and look at the publication page.
How to learn without paying for it
- Read the publication page of everything you own. Publisher, imprint, printing — it becomes automatic.
- Compare spines across a run in daylight; fading is visible immediately that way.
- Ask sellers for volume numbers rather than descriptions. Questions to ask.
Figures
A separate discipline with the same rules as any boxed collectible: decide boxed or loose, and store out of light. Collecting toys.
Store it from the start
Upright, supported, out of direct light, off the floor. Spine fading across a run is the thing a buyer sees first and it is preventable. Storing manga.
Questions people ask
Is it worth buying an incomplete set cheaply?
Only if you have checked what the missing volumes cost.
Should I keep dust jackets?
Where an edition had them, yes — and protect them.
Reading copies or collector copies?
Decide, and be consistent. Both are fine.
More: buying manga, how it is graded.