A good stringer for under 700

[Bobo96]

I'm starting to break strings quite often so I think it's about time for me to buy a stringer, and learn how to string myself. I'm a teenager and have a limited amount of money so it would be best if it was 700 or less. The most important thing to me is that it's high enough quality that it won't effect the playability compared to if I were to string it with a more expensive stringer. Any tips and knowledge appreciated.

Thanks!