Single Malt & Single Hop (SMASH) extract beers can be a nice way to try several types of brew cheap using the same base recipe.
Light Munton and Fison dry malt extract (a must for a true smash it is only M&F base pale malt no specialty malts for head retention or color)
a hop at 60 min
a hop at 30min
and a hop at flame out
a yeast of choice
this site helps me build a lot of my recipes (and it's free)
http://www.tastybrew.com/calculators/
Here is a simple American pale ale SMASH using cascades that I've done (you can steep some specialty grains to darken color or change flavor, things like crystal malt work here, but it would no longer be a Single Malt & Single hop) It's pretty hoppy so back down a bit on the 60min addition if your not sure how hoppy you like your session ales:
06A. American Pale Ales, American Pale Ale Extract
Stats
OG 1.049
FG 1.012
IBU 40
ABV 4.8 %
SRM 2
Specifics
Boil Volume 3 gallons
Batch Size 5.5 gallons
US-05 Yeast
Fermentables
6.00lbs Light Dry Malt Extract (munton & fison it's a buck or two more but worth the extra. The best dry malt extract on the market in my opinion. I still use this when I do a partial mash of a BIG beer that I can't mash all my grain)
Hops
1.00 oz Cascade Pellet 60min
.5 oz Cascade Pellet 30min
.5 oz Cascade Pellet 1min
Yeast
Fermentis US-05 dry yeast
Just simple changes in hop type & amount and yeast choice will make a big difference in final product. To stay cheap experiment with dry yeast...
Hope this is more what you where looking for!
Oh add last few pounds (2lbs) of the dry malt extract to last 15 min of boil. You'll get better hop Utilization and it will help keep the color from darkening due to Carmelization of the sugars in the boil.