Sell a copy from your collection

Most collections hold a few things the owner would let go. A second copy of an edition, a duplicate pressing, the one you bought before you found a better one. ctlgs lets you mark that copy as for sale on the entry it belongs to, so somebody looking at the same object can see it is available and write to you.

This is a small first version, built to find out whether people want to buy and sell here at all. What it does and what it leaves alone are both short lists.

A listing hangs off a copy you own

You do not write a listing as a separate thing. It attaches to one of your copies, which means the copy has to be in your collection first, with whatever condition and notes you gave it. Adding one is covered in collections and wantlists.

That is also what makes a listing readable to a stranger. The entry already pins down which object this is — this printing, this pressing, this run — so you are not describing it again in prose and hoping the buyer reads it the way you meant. What you own, down to the copy is the longer version of why the site is built that way.

One copy can carry one active listing. Own two of the same edition and you can list one and keep the other.

Putting a copy up

Open the object's page — an Edition, Release, Poster, Comic, Gear or Hardware entry, depending on the catalog — open your copies, and use List for sale under the copy you mean. Those are the entry types a copy can hang off, so they are the only places the control shows. The form asks two things, and both are optional:

• Price, with a currency chosen from a list of sixteen. Leave it blank and the listing reads "Make an offer".
• Ships from, free text up to 120 characters. "Berlin, ships to EU" is the kind of thing people write. It is not the copy's location field: where you keep something stays owner-only and is never shown to anyone.

The form says the part that matters most: your listing is public, even if your collection is not. It shows the entry, the condition, your price and where it ships from. Nothing else about your copy and nothing else about you.

What everybody else sees

Further down the entry page there is a For sale section, visible to anyone, signed in or not. One row per listed copy, newest first, showing the price or "Make an offer", a condition badge, the seller's name linking to their profile, and the ships-from line if it was filled in.

The condition is read off the copy as the page loads rather than frozen onto the listing, so if you regrade the copy the row changes with it. The scales differ by catalog, and condition grading explained runs through them.

There is also a page per member of everything they have listed, at /listings/{username}, linked from a For sale section on their profile. It is read-only: a page to hand out, not a second place to manage anything.

Contact seller opens a forum message

The button on a listing opens a private message on the forum, with the recipient, a subject and a short body already written. The body carries a link back to the entry, because a seller with several copies listed needs to know which one the message is about. One account covers the forum and the catalogs, so there is nothing new to join.

After that it is between the two of you. ctlgs never handles money. There is no checkout, no fee, no feedback score and no order tracking, and nothing on the site knows whether a sale happened. You agree the price if there isn't one, and settle postage and payment between you. Is ctlgs free? says the same thing from the other direction.

Changing a price, or taking it down

Both happen where you listed it. Edit reopens the same form with your values in it, and saving changes the price, currency or ships-from in place — dropping a price is the commonest thing a seller does, and it should not mean withdrawing and starting again. Unlist takes the row down, and you can reach it from your own copy or from the public row. Deleting the copy takes its listing with it.

What this version does not do

The gaps are deliberate, and knowing them saves you looking for them.

There is no sold state. When something goes, unlist it — that is the whole mechanism. There is no expiry either: a listing stays up until you take it down, so clearing out a stale one is on you.

You cannot browse or search listings across sellers. A listing is found on the entry for the object, or on the seller's own page. There is no badge on your collection page marking which copies are listed, and no filter for them.

And ctlgs makes no promise about the transaction. It puts two collectors in touch over a shared record of exactly which object is being sold, and stops there. That is a modest thing to do, and it is the part the site is good at.