It helped me to hoard some XP, but I still haven't bit the bullet on what to spend it on. IMO, $30 is the best amount to spend if you're going to buy anything. Any purchase at all gets you permanent +50% XP for VIP status, which is a nice bump. The amount of gold you get is also enough for either two 90-day boosters or one 90-day and whatever daily deals you snag along the way.

My write-up was actually a few weeks old and based on my early experience. While I still think Technician is one of my favorite classes, I've spent slightly more time going Juggernaut. Mortars are so much fun. Along with that, I've unlocked Doombringer and played the role of Heavy on Flag (though I don't have mines yet).

So, I still need to decide what to unlock with my ~170k XP. The TCN's Thumper is high on my priority list, but so are Doombringer Mines and the Juggernaut LMG. I might unlock one with xp, use the rest of the it on perks & armor upgrades, and hold out for a 60-70% daily deal on one of the other desired items.