There are certainly less expensive options out there.
The Dillon 650 was my first choice and I built up my press gradually. I am very happy with it. I have broken parts and Dillon came through with warrantied parts in a couple of days.
I will point out that the 550 must be indexed manually, the 650 indexes automatically, reducing the chances of double powder charging.
I also like the 5 stations on the 650 toolhead vs. 4 stations on the 550.
But that is fodder for another thread. This thread is about inexpensive ammo, and I get mine from my basement. You can also get yours from your basement/garage/spare room, and it will be cheaper than any you can buy. The tools you can use vary, but they all get the job done.