Sorry I havent responded sooner, I was on vacation.
If you can get the same speaker boxes built and installed for less than $300, I'd say go for it. I know that I have over $100 just in materials (carpet, wood, hardware and supplies). $60 would cover shipping to nearly anywhere in the US for both sets of speaker boxes. If you wanted to pick up the boxes I'd give them to you for $250.
The panels themselves are selling for more than what I am asking for the boxes and panels elsewhere on the net.
I asked around local stereo shops and they all said the will charge around $200 for a custom box installed. Carpeted would cost more. Let along 2 separate boxes.
There is a lot of time involved in making the boxes. I am not in it to screw people and take thier money. I enjoy doing things like this and am just trying to help out the B-body community.
As for hearing it, I do not have any ports in my rear deck, and I hear them just fine. I am very happy with them and the way they sound/look. Of course my opinions are just that, opinions which are biased because I built them.
If you know of any ways I can better the boxes, or cut costs, please let me know. I'd love to sell the boxes for a cheaper price, since that would open the door to more customers.