I think $10 (and less), can get you some really good cheddars. In fact, for the most part you can spend around that or spend over $30/lb for something like BleuMont's bandaged cheddar.
Something that is very much a supermarket cheese, the Black Creek, from Saputo, is more than satisfactory. I'm trying to get the Locla Beet's cheese guy, Nick Lush (who sounds like the lead singer of a early 1980's English rock band, no?) to write about how good commercial cheese can be.
Not as widely available but good mid-priced houses include Maple Creek, Widmer, and Hennings. I think you could be fine with any.
About the only time I buy non-Midwestern cheese, I buy Jasper Hill's cheese. Their cloth cheddar is more than $10, but Whole Foods frequently discounts it to something close. For the money, there's no better cheddar...for the money to save my locavore cred.
Think Yiddish, Dress British - Advice of Evil Ronnie to me.