I have been upping the level ( OG) of fermentables in my homebrew. Now, when I do the math, I am trying to get near 8.0 ABV. I end up coming up about 10.00$ dollars more per 6 gallon batch than buying ???? I can get a 6 pack of scottish ale for 8.65$ ???

What gives ???

Is the markup on malt extract that high ??? Are they using sugar to up the percent of alcohol ????