Oh, yeah, the 5,000,000 is the in-game "studs" (as in this one type of small Lego piece) currency. There are usually eventually extra abilities unlocked to purchase from collecting items and/or turning them in for quests (in LOTR) to multiply the collected studs by 2x, 4x, 6x, 8x, and 10x and they even stack! yielding an ultimate multiplier of 3840x. 10x on the 3DS version of LOTR is... 20,000,000 studs to buy, though. :O

I haven't checked recently but I really thought the console versions priced silly extras like "disguises" (This is kinda hilarious in LEGO SW: everyone down to the AT-ATs iirc gets those ~Groucho Marx glasses.) at more like 500,000.