I had Prokits on my 3 sedan....they were awesome. About 1" drop all around. I didn't have any problems with curbs or speedbumps after the drop (you do need to go slow through those though.)

You will be voiding a part of your warranty. Only way to get around that is to buy Mazdaspeed springs (basically the same as the Prokit) and have them installed by a certified Mazdaspeed dealer. I installed them myself. Not a terribly difficult job.

 

Purely from a cost standpoint, you can do better by about +/-$25 if you do some shopping.
Be sure to get the car aligned afterwards or your tire wear, especially in the rear, will be awful. You might also consider getting a rear camber kit for this reason.
And like sst said, it has been done by many in their own driveways. Perhaps your well-versed friend would lend you a hand and save you some $$$?

 

My friend got everything done in the shop :S

So I guess I can assume $160ish for tints and about $400 for springs after installation?

 

I paid 390 for mine, but they are not a site sponsor, but that includes the Camber links also.

 

I also have the Eibach Pro Kit and Mazdaspeed camber links. I absoultely love the ride and handling this set-up provides. I have not hit bottom on any speed bumps or pot holes and the car looks great. I think it is one of the coolest mods you can do to these cars from a cost / benefit standpoint. I installed mine myself in about 4 1/2 hours. Very straight forward.

 

lol i got some ebay springs, payed a total of $45 did the install myself showed it to my dealer and they were dam that drop looks way better than the ms springs. and then they took it in there bay inspected it and was like good job your warrenty stands

 

^ You lowered an automatic?

 

dont hate :P low and slow