I developed inventory and order tracking software tailored for local auto repair shops and spare parts dealers. My initial plan was to charge a one-time license fee of 24,000 TL per customer and install it on their own machines. An industry consultant I spoke with strongly urged me against selling traditional licenses, insisting I pivot to a Software as a Service (SaaS) model with a monthly subscription of around 1,200 TL.
Right now I'm a solo developer. If I switch to a SaaS model, all the operational burdens—server hosting costs, uptime guarantees, database backups and chasing down recurring payments—will fall entirely on my shoulders. On top of that I have serious doubts about whether small, traditional auto mechanics will be receptive to recurring monthly credit card charges.
As a solo dev is this transition actually profitable? What exactly is Software as a Service, at what stage does it become more sensible than one-off sales and what metrics should I look at when deciding?