“The biggest cost by far is the hosting — it's like $2,500 a month. The tools come to about $1,000. The office, the co-working, is $150. The total margin is 85%.”

Solo SaaS at 85% margins: $2.5K hosting, $1K tools, $150 co-working

At $23K MRR, fixed costs run roughly $3,650 a month: hosting, a stack of SaaS subscriptions, and a co-working desk. No team, no ads, no investors — which leaves 85% margins as the default state and removes any pressure to grow faster than the product can support.