If you want to do some resawing work, you need to make sure that you get a machine that will be stable, accurate, durable, and precise. Whilst some can use hacksaws, which are operated manually, the operation will not be as smooth as when you use an automated machine such as a bandsaw. Your hand will never be able to compete with the precision and stability that comes with using a bandsaw.
You can use a hack saw for resawing, but you can also use a table saw, or a band saw. Whilst a hack saw is manual, a table saw is automated, just like a bandsaw. But the two are still different, and a bandsaw still has one up on all three. One of the other advantages of using a bandsaw to resaw is adjusting the blade guide to accommodate a wider lumbar.
The continuous blade on a bandsaw is what contributes to having smooth cuts. It is more stable and uniform. This is something that you will not find on the manual saws or table saws. You can get the cut you need using a single pass, and this gives you straighter edges.