I think a combo of both Xarthor's idea and DJBMASTER's idea combined.

A struct is a good way to store the info you want, and search the forum
for another Database tool other than MySQL. Its a bit big for what you want.
There IS another database tool that exists as "just" a DLL for lite-c
and thats all. Cant remember where it is though....

Mind you, I single array of 50,000 elements to contain every single type of item
and every single propery of EACH ONE, doesnt really sound TOO big...
But I WOULD suggest using "malloc" to build your array out of structs.