This is in the ball park for a patent being filed and managed internationally (say Japan, USA and Europe) through all the stages to grant. Which takes ~5 years. And then over it's life cycle - there's a lot of admin. I've been regularly quoted £20k.
Yep. I filed through through WIPO for worldwide priority. Eventually my finances stretched as far as obtaining an Australian patent and a US patent. EU was going to cost tens of thousands for low probability. Chinese patent would've cost another 10k at least and it would be a gamble on the future state of IP enforcement there.
There will be more expenses. $50k was the get as far as the US patent. I've spent another $3k since then on costs arising from other paperwork around it.
That's a cheap patent. Especially given the timescale. Look at it this way. Can you find a lawyer to help shepherd a patent for 5 years and his/her fee is less then 10.000 dollars per year?
I kept down the cost by doing a ton of the legwork myself. Lots of drafting, diagrams, picking apart the examiner's citations etc. But for a lot of it you absolutely need a professional to help.
...and there are ancillary patents, for defense of the original patent, that need to be filed in order to keep up with competition. I have a buddy who has several patents for polishing concrete vertically https://www.youtube.com/watch?v=ZMSR0R8tA8A