English: Person who offers same service or product for less than a competitor in order to score more customers and market share.
Urban: Dat muvfukka who always comin up in here 'n gettin' all up in my shit talkin' bout how he roll. Playa hatin' ho stealin' muvfukka! ( I went to college in west philadelphia I am fluent in ghetto)
If someone is selling 1 ounce of weed for $100, the low-baller will offer 1 ounce of weed for $75 in order to make a quick profit and killing the competition regardless of quality. The 100 an ounce might be of good quality with no stems or seeds, but the $75 bag will be regular crappy american skunker with stems and seeds. The low baller here is riding on making a quick buck driving the market prices down.
Geek squad offers a service for $249.99 to come to your house and fix your PC. Most people around my way will do it for far less. like $50 dollars. thats geek squads fault. I hope they go out of business.