You want to try the prick and stitch technique but do not want to spend out on a purpose made pricking tool until you are sure you will enjoy this card making technique. The solution is to look for a sharp pointed object that you already own. Here are some suggestions:
A drawing pin (thumb tack). Some drawing pins have a large head that will enable you to hold them firmly enough to repeatedly prick the holes in your card.
A hat pin. These are between 2 and 4 inches long and have a small ball at the blunt end.
A safety pin. These are best pulled open so that they form a reasonably straight pricking pin. You might want to wrap some self-adhesive tape around the clasp to make it more comfortable to use.
If you are going to make a lot of stitching cards then a purpose made pricking tool is a good investment. There are several designs available. I like the single needle tool made by Pergamano (illustrated above). Its primary use is for parchment craft so has a fine metal pricking pin. This is mounted in a triangular shaped plastic handle which make it easy to grip.
I would be interested to hear what you use as a pricking pin. Let me know by adding a comment to this post.