The biggest issue right now is the transition. We have an old economy, and a new. So far the only thing they have said, is we need to find a good medium ground.. But honestly i don't know why that is. What they need is a good transition.
they need a fully working economy for the future, and they need a way to transition from the old. To me leveling tokens is the way to do it.
It only needs to classes.
First class, If you paid for the mech with MC, give it a token. You paid money, here is a bonus, You can level that mech under the new system for free. Presto, easy peasy. No cost leveling to you. Thanks for buying/supporting us. (most folks will get something from this, some folks could get a lot.. The down side, is the token is only for this mech, and works one time.
the Question, Should it be for every mech you bought or"special versions" like +XP /C-bill booster mechs? Should it be a strait 1-1, or 2-1, 3-1?
Second class.. People that are kinda like me, Not many bought mechs with MC, but played a good amount and worked the system. Give these FTP players leveling tokens based on Matches played. Matches played= money/time.
This would mean that you could just get a single token say at cadet.. Maybe another is added every 50 or 100 matches.. (what this actual number is i don't know. Maybe it is dynamic, some early easy tokens, make it harder to earn tons. It could also have a Max cap.
Basically this solves both issues. People that played a lot but worked the system to not get left out to dry due to them just really playing the system. Those that bought a lot with real money, and are more casual won't be left with a 500m price tag..
the first class tokens never expire. First time you level your paid mech, it's free a PGI thanks to you.
Second class tokens i personally think should have an expiration date. Maybe a month? the reason being is to keep folks from keeping the 30 tokens, and use um as they get a random new mech for the next 3 years and pretty much just break future economy, for what they really are is to transition your already owned mech. .A simple flag on the account showing when a mech was bought. Then just remove the unused tokens at a later date. I say give some time, so people don't have to spend hours leveling tons of mechs up.
They could also be on a timer, so those that are taking a break, don't get the timer started till they log in their account. Sorta a premium token timer..

Now you work on 2 things.. the transition economy, and the future economy.. They have no reason to be connected in any way.