... Advents only give 10 Silver 10 Gold. You basically only get about 10 books per event and up to 30 books per month, plus a a few more from 2 sets of GO. You need 50. That's hardly enough at all. Also, just because you're not a whale doesn't mean you should neglect MLBing SRs if you want to be competitive in Tower otherwise why bother with unlocking T4 at all? Unless you're hoarding 100k jews like Cobble is doing, then sure.