Here is the proof, check the picture below. Not speaking about every 20 gold fuse i had to use. The game will get very expensive at some point: the only way forward is by playing the game and having patience with it. Especially gold related. Buying enormous amounts of gold will never save you. New dinosaurs will be announced and the circle goes round again. Maybe even level cap increase; it will never stop (classic example; pogo).
As @OWDSKL said: best way is to spend cash on speeding up incubators. With vip you get 1800~ cash / month. If you speed up 180 3h crates at 1h (10 cash) you will most likely end up with loads of 8h, 12h and 24h incubs + AND save loads of hours / month. Instead of 8 3h / day you can now do 12 3h per day (just the math; its not possible due to sleep for example). You dont even have to spend more money; only VIP. 10€ already pays itself.
For gold; 1500 cash = 75.000 gold, 300 left. 180 3h incubators = 180h of waiting time avoided but especially 72.000 gold (level 11, arena 7 = 400 gold). Slightly less BUT you also got loads of darts and especially DNA which speeds your general progress. The instant gold buy doesn’t; you still need darts, 180h and DNA. You even get more 12h and 24h if lucky since theres more empty spots vs. full of 3h incubators.
Doing battles in the arena also has a daily coin cap if im correct. Still worth it if you know you can beat opponents ‘easily’. Unlike arena 7 where the AI is ridiculous lol. Rather wait for incubators and go outside, spin some supply drops haha feelsbadman i need gold.