So I shouldn't use some on any axes or exp bonuses or cool stuff? xD I should use it all on BM? @Kσrim @AtlantaFalcons
I know you have only 40k zp as of now, but if you're looking into having EXP and GP bonuses in a long term plus a nice weapon, you should just buy AK beast(not even mentioning fury, unless you're fun of your kdr for ribbons etc./even tho fury gives you more GP and EXP bonus), it will be a waste of money if you buy +EXP temp items when you want EXP bonus forever including other perks. It's already a waste of money buying VIP weps, but it will sure be more economic in the long run.
The rest is really up to you. But I would strongly advise you to try your luck in BM, 'cuse even tho you don't get any ZP wep you will have coupons + GP to get good GP guns and with the enough coupons, it will eventually worth for a ZP perm wep. But you should invest more into that account if you want to make it your main. As for ZP chars, since you like M4's, buy SPOP char(and fuck who says it sucks, you don't need any other char if your priority isn't being attractive xD, further more you can always buy another char which suits you best) for an exclusive ribbon and try to get enough ribbons with ZP for the M4 CC through the process and other perks.