You get 2 bottles for $7.99. In my opinion, this is one of the best available. It's the same stuff that the GM dealers sell for $25.
In Store or online at Advance Auto Parts.
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Techron-Concentrate-Fuel-System-Cleaner-(12-oz-)-Chevron_7081073-P_N3232_T|GRP2030C____
Chevron Techron Concentrate Fuel System Cleaner (12 oz.)
Product Features:- Designed for carbureted or fuel-injected spark-ignition engines
- To help keep the entire fuel system clean, use Chevron Techron Concentrate every 3,000 miles
- Suitable for use with diesel fuel in light-duty indirect-injected diesel engines
- Not recommended for air-cooled 2-stroke engines