Aftermarket intake questions

I am very happy with the performance of my Miata, but I am wondering if I
can improve my current performance AND fuel economy with an aftermarket
intake. Here is the rub - I currently get an AVERAGE of 30 MPG in daily
driving, which is, from what I understand, better than average economy for
my perfectly stock vehicle. I am hesitant to screw around with anything that
may decrease my economy and cost me $200 to boot. Logic tells me that the
intake would increase the fuel economy even more, but I've been burnt in the
past using my logic. I just drive the car as a daily driver and don't need
ultimate performance from the new installation.

1. Has everyone who has switched to a short ram system noticed an increase
in MPG?

2. Is the performance and MPG increase worth the money and time investment?

3. Should I go with a short ram system, or just switch to a high-flow K&M
filter?

4. Which short ram system would be the safest bet?

5. Is it worth the extra installation headaches and $$ to get a cold air
system?

--
Boreal
2001 LS 6 speed Silver/tan, Sport Suspension w/hard rear sway bar