If you already own a compact tractor, a three-point backhoe attachment looks like the cheap answer. Sometimes it is. Often it is a machine that digs slowly enough to cost you more in hours than it saved in dollars.
This page compares the two honestly on the things that actually decide the job: cycle time, stability, ground damage, and what you give up when the attachment is on.
Own a tractor and dig a handful of times a year? The backhoe attachment is the cheaper, sensible answer. Dig monthly, work on finished ground, or trench any real distance, and a dedicated mini excavator pays for itself in saved hours and repair-free lawns.
A tractor backhoe repositions by unpinning, raising outriggers, driving forward, and setting up again. A mini excavator walks itself two feet down the trench in five seconds and keeps digging.
On a 100-foot trench that difference is most of a day. If you dig a few times a year, that is fine. If you dig monthly, the excavator pays for itself in labor.
You already own the tractor, the shed space, and the trailer. A backhoe attachment adds digging to that for a few thousand dollars, and it comes off when you need the tractor for mowing, hauling or loader work.
For a small farm that digs a post hole here and a drain line there, it is the right answer and we will say so.
Tractor tires plus outrigger pads concentrate weight on small footprints. On a customer's lawn or an irrigated field, that leaves marks you may end up repairing. Tracked excavators spread the same weight across a much larger area.
For occasional, shallow digging, close enough. For production trenching it is much slower to reposition and rougher on finished ground, which is where a dedicated excavator earns its price.
Attachments run roughly $3,000–$9,000 assuming you already own a suitable tractor. New mini excavators start around $6,580 here, so the gap is smaller than most buyers expect.