I think it’s completely up to you; as long as it’s an investment that will be worth the money and you will get lots of use from. If you do a lot of jumping and think it would be worth it to yourself to get one, then it really doesn’t matter how high your jumping if the saddle is getting lots of use.
For me it depends on how much you are competing and jumping. Me, personally, would get a jump saddle around 1m - 1.10m+ but if you are comfortable in a GP saddle then I would stick with it
Hope this helps