Joining two ethernet cables: strip and solder or buy an adapter?

CAT5e/6 junction boxes are available for splicing cables without needing to terminate, twist, or soldier.

Junction boxes are better for permanent cabling, as they're more secure than terminated ends paired with a coupler, or twisted/soldiered. Cables with these junction boxes won't be pulled apart at the splice point, unlike with other splice methods.

Examples:

• Punch-down junction box
• Punch-down 110 block
• Punch-down shielded 110 block

Note: I've never actually purchased from any of these particular storefronts. I'm simply linking to them to show examples of junction boxes.

In a pinch I've been known to strip it, twist the inner wires together together, and wrap with electrical tape. Its a ghetto soluton, but effective if you do not move the cable around to much. That being said that coupler is like $2 so it seems like you have several good options.