Played for a few hours, got 1,000 points and bought a shirt.
Every time you rank up you get a random item for free. If DoI is anything to infer upon, the colours in the corner tabs of the items represent probability. Purple being rare drops, yellow being common drops.
Based on the previous Alpha/Beta, it appears the more you rank, the slower you rank.
So while I agree the prices are high, if you know what you want, it'll be completely achievable for both characters within reason between levels 20-30.
After this point ranking really slows down. Since ranking is what gets you random unlocks and also currency, it seems reasonable to me although it certainly has its shortcomings. The initial influx of cash and high pricetags will ensure everybody gets to be unique, but your purchases will begin to feel special as you rank up and they become fewer and further between.
I like the random unlocks on my insurgent though, guarantees a truly middle eastern appearance of being dressed atrociously and also randomly as I focus on my Sec.