I had a sump box and 2 fittings done by Sean Mullins Race cars, and it was $100 supplied and fitted.
All other quotes were about $180 - $220
Sean has now stopped race car fabrication, and now builds kids play equipment, but he may still take on a small job like that.
He did 2 tanks for me, and I was happy both times. Both were on used tanks, not new ones. I then took it to a radiator shop, and got them to paint it black for me.