[HitandRun]

If you are looking to buy only MOC/MIB items you may want to stick to the later vintage Battle Corps era stuff as the more common figures and vehicles run a little cheaper than the earlier years of the run.

If you are ok with buying used figures I would recommend checking out the GI Joe figure/vehicle and accessory lots on ebay. Sometimes you can get a real bang for your buck with lots.

If you are open to 3.75" figures from the early 2000s - the Spy Troops, VvV, Joe vs Cobra figures and vehicles mostly seem to be cheap and readily available. There are exceptions of course in terms of cost but this is probably the most cost effective line to collect. The vehicles would probably stand up better for a 3 year old as well (I have a two year old myself...I know how they can be ) And there is alot of carryover with the characters from the ARAH era to this time.