I realized this after I did a month long experiment where I basically turned MWO into a second full time job using every "Real Money" advantage I could and only earned 87 million.
So finding myself needing roughly 45 million C-bills just for modules in less than 14 days and due to the low C-bill rewards even while using Premium and hero mech plus the extreme investment cost required to outfit 4 mechs with their own set of unique modules. I ended up selling off 3/4 of the IS mechs I previously owned plus about half my stockpiled IS (and some extra clan) weapons and equipment.
Even after all this, I am still 18 million short

On the upside. I now have have quite a few free mech bays so I won't have to buy any of those any time soon.
The point is, the economy is brutal and needs a boost although dropping module cost would help alot. Also it is costing PGI money. If I had been making enough C-bills between using hero mechs and premium subscriptions to play for the things I needed and wanted, I would never have sold off any of the IS mechs I owned. This means I would have had to have bought more bays as I expanded my collection. Instead the lack of income ended up forcing me to sell off mechs that, while good and enjoyable, I tended to play less often in order to outfit the mechs I intend to use in CW. This shouldn't be happening, not for a player who has invested significant amounts of real money into income boosting products and services like premium time and hero mechs.
Please review and fix PGI.