Economically you can convert between a fixed price and a subscription price. A subscription has a fixed economic value governed by the interest rate. That is if you have a thing that generates $10 every year, you should be able to sell it for $200 (if the interest rate is 5%.)
I think this is something people don't often think about. But it makes it very easy to compare different costs and benefits that involve time. E.g. imagine a building is costing $1000 a year to maintain, and a new building would cost $50,000 to build. You can figure that it would be easier just to invest $20,000 and use the interest to pay for the maintenance. And save $30,000.
But if building a new building cost only $10,000. It would be a good investment. And you would expect to save more money than you would gain from anything else you could invest in with that money.
The same logic applies to subscription fees. If a software license costs either $120 a year, or a fixed price of $5,000. You should prefer the subscription. Hypothetically you could just invest $2400 and use the interest to pay the subscription. Saving $2,600.