Can someone tell me a good way to get miraclous fossil rocks easily without..

You sound like you're kind of early on in the game. Money can sometimes be a problem when you're trying to upgrade everything but you should know that as you progress, you will amass money faster than you can spend it. So, my advice is to grit your teeth and ge the upgrades for both sonar and tools. You will not regret the money spent, believe me.
If you really won't get the upgrades, the only way I know of is to do the side mission where you give dropping fossils to John Guano in the Hare Club. After the initial trades, he will start giving you a miraculous rock for each 20 dropping fossils you give to him.
Oh, and if you help the guy at hot springs make hard boiled eggs, he will give you a gold rock if you do exactly 10.00 seconds. Watch the little talkie balloon over his head; the second dot in the seventh balloon marks 10 seconds. I've only managed it once so far, so I don't know if he'll keep doing it
Also check back on other questions in this thread; lots of people sent in really good ideas on this very question. Good luck!

You can wear the neutral type mask and search at treasure island and youll find some wonderous and miraculous occasionally.

A little to much information about you t-rex :wall: umm... An easy way to get 1 is to wea a red mask and go to icegrip platue, once you beat the game you can get 1 if you clean 100 fossil rocks at the hae club :wall: or to complete robo dons puzzle with no mistakes 5 times in a row