Two tips:
1. Don't focus just on the cost of the software. Look at your total costs...
2. If you really want to stay cheap, and you don't need any help, a QuickBooks desktop flavor like Pro costs you $200 and you can use it for several years. In comparison, Xero or QuickBooks Online cost $20 or $30 a month.
P.S. Full disclosure: I'm author of QuickBooks for Dummies.
P.P.S. For our CPA firm, we use QuickBooks Online and though Online not as powerful of Desktop, we recommend clients use Online because it's easier and cheaper for us to help