I was hunting around for a portable air compressor on ebay and came across this company, Q3 Innovations . They sell a compressor that looks a lot like the Viair 200P but for only $50. Here's a pic of each.
Q3:

Viair:

Any chance they're the same product marketed by two companies or is the cheap one just made to look like the other? Somebody buy one and let me know what you think of it.
-Michael

 

Convert their specified flow rate of 35 Lpm to cfm, then compare it to the QuikAir, Viair, etc.

For tires it's the cfm that's important, not the high pressure rating.

 

35 L(itres) per minute is equivalent to 1.236 CFM. Not a lot.

 

I can't find a flow rate for the Viair products but I can for some others.
Quickair 1 only flows 1.13 cfm at 0 psi but the Quickair 2 can do 2.18 cfm.
Extremeair Jr. does 1.5 cfm and the Extremeair does 4 cfm.
So it looks like this Q3 compressor is probably closer to the lower end units other manufacturers have out there. I think I'll wait till I can afford a better unit.
-Michael