IMO, these are the only two stand alone processors that have enough quality for the price, but they are still fairly expensive.
these machines are excellent;
http://www.tlaudio.co.uk/docs_07/product_07/EQ-2.shtml
http://www.tlaudio.co.uk/docs_07/product_07/C-1.shtml
TLA make different series of valve processors, but the classic series is much better than the project studio ivory series, to be honest i dont think the ivory series are good enough. (i've got one)
you get what you pay for.
Toft audio do a nice combined dynamics processor, which is cheaper but not as flexible;
http://www.toftaudiodesigns.com/atc2.html
i dont think its worth wasting money on budget outboard gear, better to save up till you can get something decent, which will last you forever.