Just worked! But with a Little modification to the video (in my case). When adding 1 to all the result, i've got only 201 and 202 but multiple times (i've got 1350 results, half 201 and half 202). So, the value of stamps now was 201, so i've tried starting to the address 70xxxxx to the 89xxxxx, and i found the right one after a bunch of address modification. I've tried also restarting game, but i get everytime only 201 and 202..... bah.
So, i'm happy that now i can buy better weapon, i don't like cheating damage and healt, that will be too easy. Thanks a lot!
P.s. I still don't know what is X4, i have to find some time and learn cheating better!
Ah, in the screenshot you can see a glitch by modify the wrong number xD. I've got also a beautiful pink screen.....