More money = more manufecturing lines, more dockyards making warships. There will always be new technology to explore, a higher budget won't stop them from doing that. It would help them transform prototypes and concepts into usable tools. The 002 being built now would apparently use IEP. These would be the largest IEP ships ever designed, lack of widespread IEP seems to be a prime example of budgetary constraints holding back the fleet's combat potential (through not by much, 055s have excess power due to large on board generators compared to similar ships) Railgun itself is a cost cutting measure compared to expensive arsenal ship concepts.