Do the daily bounties, level up Shaxx rep, and just play. You'll get plenty enough trophies in due time. You just gotta remember that this event still has over a month left. Shaxx has multiple large sums of trophies at certain ranks, and you can get some from doing his bounties too. Think about it this way, if you get about 2 or 3 every 10 waves, then let's just say casually you'll play an average of just 30 waves a day, that's 6 to 9 a day from that. Then there's a total of 100 trophies from Shaxx's rep. So far that's coming up to about 340 to 460 over just 40 days (which is still not as long as the event will last), but there's more ways too. Assuming you do at least just 2 of Shaxx's bounties a day and 2 of Arcite's weekly bounties, that's another 64ish, but then you also can get them from other game modes, which could easily add up over time. Now what I've stated here is very very lowball amounts at playing extremely casually, but consistently. If you just play the game and participate consistently, you should have no problem amassing at least 450 trophies by the end of the event. If you want it, just work for it. That's all it takes. Oh yeah, and it also takes a bit of willpower to not buy weapons for trophies until after you get all the armor.