QTR-Quadtone RIP

All,

I have been a QTR user for a few months using an Epson R1800 with 
the stock Ultrachrome inks.  Last weekend I installed the K7 inkset 
and began printing.  I ran two 8 x 10 prints that were stunning.  I 
was ecstatic and said to myself that I had finally reached the point 
where I was ready to leave the wet darkroom for good.  

The next day I hoped to run some final 11"X14" prints on Hanh photo 
rag.  I found that I had to run three head cleaning cycles to get a 
clean print and after printing two prints, got an out of ink warning 
on one cart.  After spending almost $ 150 for the ink set, I was 
stunned to find myself out of ink so quickly. When I checked the 
other carts they were all down below 50% as well with some much 
lower.  I then noted that the K7 carts seem to have inserts that are 
slightly smaller than the stock carts and thus must contain less 
ink. At a price of $ 25 or so per print, I know that I'm not going 
to be doing this for very long.

My question as a semi newbie is:  Is this typical and is there any 
alternative to this astronomically high ink cost?  I have looked at 
the Niagara bulk ink system but its cost, coupled with $ 44 per 4 
oz. bottle of K7 ink (times 7) yields a $ 607 solution.

Anyone have any thoughts?

John G.