The lease detail most property buyers get wrong
Most buyers see a lease at below-market rent and read it as a problem to negotiate around. Often it's the reason they have less competition to negotiate against.
Here's the mechanic most people miss. A property with six months or more left on a below-market lease can't deliver vacant possession any time soon. That rules out most owner-occupiers immediately, since they need to move in within a reasonable timeframe. It leaves investors, who are comfortable holding an existing tenancy, as close to the only buyer pool left. First home buyers who don't need to move in straight away, for instance those still living with family, are one of the few exceptions. Occasionally you'll find a lease considerably longer than that, which cuts the buyer pool down even further.
Fewer buyers changes the negotiation. Less competition, on its own, tends to soften a price, which improves your starting yield even while the lease is still under market.
That's before you even ask why the property is on the market. A seller carrying an under-market lease often has a specific reason for offloading. Sometimes it's tied to the same lease keeping other buyers away, not just uninterested owner-occupiers, but a seller who's been waiting for the right kind of buyer to turn up.
The upside shows up later, at renewal. Either the existing tenant renews closer to market rent, or the property becomes available to re-lease at the current rate. One client purchase illustrates this well. The rent was under market at the time of purchase, and within a year of settlement, the tenant broke the lease early, and the achievable rent had moved from $600 a week to $650. The gap that made the entry price negotiable became the gain once the property came back onto the market.