Having sold my voltedge after aquiring a more powerful brandish (better UVs) I realized one simple thing: Krogmo coins are still hard to get, maybe even harder than ever.
Reason: Voltedge recipe costs 150 coins, Boltbrand costs 100 coins, Shockburst Brandish costs 50 coins. Total: 300 coins. To get 300 you need 150 games if you win each and every one, around 280 otherwise.
5 krogmo coin boosters, that come free with $25 energy purchase (ha, pay $25 to get "free" items) will get you 5 extra coins per game. So with 5 boosters (last for a day) you get 6/7 coins a game, which means you "only" need to play 50+ games.
The real problem is, however, that you'd still need to spend much more time waiting for a game to start than playing. Its terrible experience, too. Very laggy (call it delay, if you like, but some packets simply get lost on their way, others are misinterpret).

Suggestions to make it easier to obtain 1-time-use recipes (you won't need 2nd item of that sort... ever):
1. Remove krogmo coins completely and make respective recipes available at hall of heroes. That'd make Coliseum games optional. You want to - you play it. You don't want to - you don't play it.
2. Make Krogmo coins available from other sources, like buying them from Sulivan. Price? 50 energy per coin sounds fair. Spiral Knights fair, where the more you pay, the less you get.
3. Make boosters pay 3-10 coins each.
4. Drop booster price significantly.
5. Extend boosted period to 1 week. Currently you get 1 day (24 hours) where you'll be eating/sleeping/doing other stuff 16+ hours. In reality its a couple of hours for 300 energy, very expensive. Weapon slot costs 250 energy for 30 days, coin booster does 1 coin 1 day, and costs more...
6. Increase value of King Krogmo bribe prizes, individualize them. Like, pay 25 energy for a random mask (regardless of the outcome, only for player) or 10-50 extra coins.
7. Remove King Krogmo bribe option and increase payout.
8. Lower recipe cost.
9. Make recipes unbound, so they can be traded.
-new-
10. Idea made in collaboration with Thunder-The-Bright: make krogmo coin booster boost a fixed amount of games, instead of 24 hours of time. For example, 30 games are boosted per coin booster, also limited by 30 days (active coin booster expires in 30 days, even if 30 games weren't played). That'd make them cost 10 energy each coin. Kind of expensive (840 crowns per coin) but saves tons of time. Currently its possible to play more games and earn more coins, but it takes up entire day.