Cheap Greenhouse Heaters

greenhouse
a building with glass walls and roof; for the cultivation and exhibition of plants under controlled conditions
A glass building in which plants are grown that need protection from cold weather
of or relating to or caused by the greenhouse effect; "greenhouse gases"
A greenhouse (also called a glasshouse) is a building where plants are grown.

heaters
A fastball
A person or thing that heats, in particular a device for warming the air or water
A conductor used for indirect heating of the cathode of a thermionic tube
(heater) fastball: (baseball) a pitch thrown with maximum velocity; "he swung late on the fastball"; "he showed batters nothing but smoke"
(heater) device that heats water or supplies warmth to a room
A heater is object that emits heat or causes another body to achieve a higher temperature. In a household or domestic setting, heaters are usually appliances whose purpose is to generate heating (i.e. warmth). Heaters exists for all states of matter, including solids, liquids and gases.

cheap
(of an item for sale) Low in price; worth more than its cost
(of prices or other charges) Low
brassy: tastelessly showy; "a flash car"; "a flashy ring"; "garish colors"; "a gaudy costume"; "loud sport shirts"; "a meretricious yet stylish book"; "tawdry ornaments"
Charging low prices
relatively low in price or charging low prices; "it would have been cheap at twice the price"; "inexpensive family restaurants"
bum: of very poor quality; flimsy