A brass and black anglepoise desk lamp lit on a wooden desk beside two hardback books, its shade glowing warm against a plain wall. — Worth a Saturday of selling. Zwaptz still tells you the number first.

A man kneeling on a rug beside three open cardboard boxes, sorting folded clothes, books, framed photographs and small china ornaments into them. — The pile that is not worth a Saturday of listing, photographing and posting.

Sometimes you should just sell it

Swapping is not better than selling. It is better at some things and worse at others, and pretending otherwise would waste an afternoon of yours before you found out.

Here is the whole comparison, including where selling wins.

If you need cash, sell it.

Not “consider selling”. Sell it. A swap hands you an object, and an object does not pay a bill. Everything else on this page assumes you are past that question.

Where each one wins

Selling compared with swapping, across six situations.
The situation	Sell it	Swap it
You need the money	Sell it. This is not close, and nothing below changes it.	A swap gives you an object. An object is not rent.
How long it takes	Photograph, write, price, list, field the offers, wait in for a collection.	Photograph it, get a range, put it up. The waiting is the same; the writing is not.
What it is worth	You decide the number, then find out over a fortnight whether you were right.	You get a range with a stated confidence before you commit to anything.
Rare, high-value, or collected	Sell it. A specialist auction knows buyers you cannot reach, and the fee is worth it.	The band around a rare thing is wide, which makes an even trade hard to judge.
Big, heavy, or awkward	A courier quote is often more than the item. Local sale, cash, and hope they turn up.	You are meeting somebody local anyway. The size stops being the problem.
You want a different thing	Sell yours, wait for the money, then start again as a buyer.	One arrangement instead of two. This is the case Zwaptz is built for.

Eight second-hand objects laid out on a dark slate slab: a scuffed skate helmet, a cast-iron pan, headphones, a cloth-bound book, three stacked hardbacks, a worn cardboard box, a wooden hand plane and a fabric-covered speaker. — Eight things with a real value and no buyer worth the effort.

What swapping is for

What swapping is actually for

The pile of things that are genuinely worth something, individually worth less than the trouble of selling, and collectively worth quite a lot.

A drill, a bread maker, two scooters, a box of records and a rowing machine. Sold one at a time, that is five separate projects. Nobody does five projects.

Appraised, it is five numbers in an afternoon, and any one of them can become something you want.

How that works is on the band — the mechanism page — and what the numbers mean is on confidence.

Five valuations a week come with an account at no cost, so it is a cheap way to settle the question. Find out what one thing is worth, then decide which of the two columns above you are in.

Get a range on one thing

Comparable sales are not being looked up yet, so today a range comes from what the model knows about a market rather than from listings it checked, and confidence is held down to match. Every valuation says which of the two it is.