http://www.nextag.com/dog-car-seat/search-html
check out this addy...there are quite a few pages that compare all dog carseats/harness systems. On page 3 for example there is a harness for 19.99 and carseats for as low as 23.99 I didn't check out all the pages but they seem to have seats in all price ranges.
Hope you find something!
