Price depends on how long the loop is.
Their is something called a Loop Station by boss http://www.music123.com/Boss-RC-20XL-i144689.music
which will give you up to 16 min
or the slightly older RC20
or the DD3 or DD6 (which will do about 5 seconds) and cost about 150 bucks.
page and www.studiotrax.net
for all things recording. my toons
Brought to you by Dr BadGAS