3 weeks ago, it is about 30k credit per dollar.
For example, 80k for a weekly pass. 150k for a section x unlock. 30k for a ship upgrade 7.
Now the price skyrocket.
Many cartel coin items simply don't even show up in GTN.
Like gold in real life, someone is hording.
Should be server-dependant. Never seen prices as low as the ones you quoted but I check those items only every few days or so. And hoarding something EA can reproduce indefinitely with a cost of zero is somewhat unlike "gold in real life".
I am not complaining about my server.
Someone clearly spends real money.
Just yesterday, someone put $400 worth major experience boost in GTN.
On the other hand, someone has lots credit to burn too.