Here is a scene that plays out in inboxes every week. You send the same brief to two printers: five thousand A5 leaflets, colour both sides, folded. One quote comes back at a price that feels reasonable. The other is nearly double. The instinct is that somebody is trying it on, and the instinct is usually wrong. Both firms are probably being straight with you. They are just not doing the same job.
Five thousand leaflets sits close to the crossover between digital printing and litho. A firm with the right litho press pays for setup and plates, then produces copies at very little per sheet. A digital house skips the setup but pays more per copy all the way through. At your quantity, one firm's method may simply be the wrong tool operating at the awkward end of its range, priced honestly. Neither is cheating; the machines have different economics, and your job happens to fall where they diverge most.
Unless your brief nailed the specification down, each estimator filled the gaps with their own house defaults. One assumed 130gsm gloss, the other 170gsm silk. One priced a single fold, the other a roll fold. One included delivery and a printed proof, the other quotes those separately. Three or four small assumptions, each defensible, compound into a large gap, and the totals stop being comparable at all. This is the most common cause of a shock difference, and it is invisible unless you read the line items side by side.
Plenty of firms that look like printers are partly brokers, sending your job to a trade printer and managing it for a margin. Plenty of others outsource just the finishing. Neither arrangement is a scandal, and a good broker earns their fee in chased deadlines and checked files. But it means one quote can contain a middleman's margin and another none, or one includes an outsourced folding cost the other does in-house. The price reflects the supply chain behind it, which you cannot see from the total.
A press hall with idle capacity this fortnight prices keenly to fill it. A firm at capacity quotes high without embarrassment, because the only version of your job worth taking is a profitable one. Quotes are partly a diary statement, which is why the same firm can be cheapest in March and dearest in June for identical work.
The productive response is not to grab the low number but to make the quotes comparable. Send both firms the same written specification: size, stock weight and surface, colours, fold, quantity, delivery, deadline. Then ask the expensive firm what is driving their price, and the cheap one what is not included. Those two answers usually explain the entire difference in about four sentences, and occasionally they surface the assumption that would have ruined the job.
Spread the net a little wider than two while you are at it. There are 2,868 printing companies listed on this site, working across very different machinery and specialisms, which is exactly why prices vary. Pick out a few printers near you, or put one tight specification out for quotes and compare what comes back line by line. A quote you cannot explain is not a bargain or a rip-off yet. It is a question you have not asked.