This bus has pros and cons.

Pros

• No need for a backplane
• Slave boards are quite small
• Connector holes are on 0.1" grid
• Connectors still available to buy in 2024
• Easy to port ISA bus designs to
• Easy to design for 8088-based projects

Cons

• Master boards have no obligatory size
• Pins easily bent
• Mounting holes not on 0.1" grid
• No edges free for sliding into racks or cases (unless you design a bus master that does)

These boards were heavily used in industry but boards are eBay are usually expensive because most people buying them need them to maintain industrial installations, and are willing to pay higher prices. Don't expect cheap second-hand stuff.