Well, aren't we nit picky today I got that from Sean and an owner of a GTS-T from Big Bear. 10-15K is the range from what I've collected, a lot of folks have to pay 15K because the modifications done usually do not pass and a need to retest which they pay for themselves (It was $1500 before, I believe they raised the price up not too long ago to $2000?). If it were that easy like you state, the importers in California and out of state would have sold imported cars. California is by far the hardest place to legalize the imports, even parts of Europe aren't as bad as California's emission standards.I don't know where you got the 15k figure from. 10k is the standard for G&K, they have a monopoly on grey market import for what is effectively welding some different catalytic converters poorly to the downpipe + main cat position and a restrictor on the fuel nozzle so you can't put leaded gas nozzles in there. This is the cost for all 1989 to 1995 RB26 GT-Rs assuming you bring them a stock car without a bunch of problems.
By the way, I decided to go and take a read of some articles about CARB against the white house since we talked about it and so it seems that indeed, President Trump wants to abolish California's emission laws all together which can benefit you. CARB's a nazi agency controlled by the left. I really hope they dismantle CARB so the left there will cry even more. And to think the state would do something good with the money they get from petrol tax and vehicle fees and fix up our destroyed roads. Just goes to welfare babies while we have to suffer financially.