Here's what I have spent so far.
BEGI manifold with gaskets $450
CX racing intercooler $66 Ebay.
Universal intercooler piping kit $100 Ebay.
Reverant MS2 PNP $680
Bosch EV14 650cc injectors $300 Ebay.
LC1 Wide band with blue guage $167 Ebay.
Oil feed and drain lines, cooling lines $100 Ebay.
F1 stage 3 clutch $165 Ebay
Auto meter boost guage $45 Ebay
Auto meter EGT $150 Ebay
Greddy type S BOV $100 used.
DIY auto tune GM AIT $25
Magnaflow muffler, high flow cat and mandrel bends to build custom exhaust $400
So I am at around $3300 for everything, it is a lot cheaper to shop around and buy things seperate, but a kit is a lot more Convenient. Just make a list and work you way down throught it.
This is my first turbo miata, but I have put together 5 turbo civics, 1 toyota 4 runner, 1 1jz swapped 1974 FJ40 and I am just finishing a VW 1.9 turbo diesel swap in a custom suzuki SJ410.