Not sure what is good as it would depend on your needs and definition but you could take a look at http://www.hotscripts.com/PHP/Scripts_and_Programs/Match_Making/index.html . They do have ratings there and there are some which are free.
And what do you have in mind? I can recommend some good softwares but i need to know what do you plan to with it so I can direct you to a good lead.
Also you can check with aedating, its expensive one but it has good features. I think you can even hire developer who can develop script below your budget, for any further assistance PM me.
php izabi is a good platform, However, I installed it on http://www.esrilankans.com/ and encounted some bugs. If your budget is 500, then you i suggest you to go for, phpfox or phpmyspace.