Quickbooks desktop does offer a recurring subscription on a monthly or annual fee but the downside is that if down the road you decide not to pay - they lock your file - even though it is on your computer.
Better is outright purchase of the stand alone desktop version for somewhere around $200-$300 which gives you a fully supported program for 3+ full years (always 5/31 of 3rd year following - 2020 is good through 5/31/2023). If you do not use bank feeds or payroll or payments from customers by credit card you can get even more life out of the product.
If you migrate to the online version that is a whole different equation and an ongoing cost that far exceeds the cost of desktop.
But offer up some more details of what you do and how you do it and we will be glad to give you mofre detailed options and suggestions