I would without a doubt shop around on the fuel pump also!
there is a place called AML (American Mobile Lube) off of Arville and Flamingo
http://americanmobilelube.com/362-5823
they guys who run the shop are named Dan and Mike
They looked at my fuel pump on my old buick and not only quoted me a price at half what another shop wanted, but actually ended up just needing to flush out the fuel injection system and changing the filter. on my buick (with the pump in the tank, not sure if it is the same on the miata but figure it must be at the price you mention) it would have been between 300-400 bucks
Also if they cant help, I would say call Goodyear. They are who I always take my vehicles to and they have always been honest with me.
I usually go to the one near Meadows mall, I am not sure if all of their locations are as reliable.
http://www.vegasgoodyear.com/about_us.htm870-8901
Without a doubt call around and explain your situation to get some quotes before dropping 900 on it... whether you sell it or not, save yourself some cash if you can.