Board Thread:General Discussion/@comment-191.177.79.120-20150423135927/@comment-31777021-20150429193325

Well, first off you should finish any research going on in any of the trees (Aircraft tree, SP. planes, SP weapons) so you can earn bonus "refund" credits by having no research going on. It's what 95% of the higher tiers use for credits, so if you need a good funding, do that. Upgrading your T-50 that way should be easy that way, since you'll gain large amounts of credits while your T-50 is fully researched for the next level, and research will go considerably faster while you only have the T-50 being researched.