Instead of using a batten lifter to remove battens, you could use a demolition and lifting tool. As it has more than one use, it could be more economical for you.
Or you could use a prising and wrecking tool. It is similar to the demolition and lifting tool and can be used to lift battens, too.
You could also use a crowbar to remove the battens, although this would be a great deal more labour-intensive and time-consuming.Also, a crowbar is more likely to damage the battens and perhaps the rafters.
A batten lifter is a hard-wearing, quality product available at a reasonable price.It will give years of safe, dependable use.