This is quite a huge amount of money since the OP said he/she wanted to gain personal experience of developing blockchain explorer.
Do you have any idea if, for example, I'll do it first locally, just for fun or experience just what like OP wants, Do I still need those 500GB of space
or minimum/DELL R200 with 4GB of ram and an old Pentium CPU just what you told?
Yes, you will still need to store all those data locally