we use a STlink v2 for €20
I have come to prefer those $5 st-link clones over the real STlink, for its small size and convenience.
you take a chance that it does not work or will not work in the near future as happened before
Using those jlink clones on newer IDEs can be a little involved,
and pissing away €20 on a fake
20euro is too high of a price. Those clones are going for like $10.
The jlink edu is a good deal, especially if you get a v9.