I always used trailers. Back then, the only one available in our town was the Cannondale rear facing one, but my kids seemed to enjoy it. (They're now both adults -YOUNG adults, I'm not that old!).

As far as cost goes, a couple of comments. Only you can decide if you can afford the cost of a good quality trailer, so I won't tell what you can and can't afford. But say it's $2-300. How much did you spend on your bike? How much did you spend on your TV? I Pod? Weekly coffee? Uber-featured cell phone plan? Cell Phone? Cable service?

You get the picture. None of the stuff you like is free, and you will like biking w/ your kids! Don't expect it to be free.

I'm rarely surprised when I hear people claim they can't afford something like this, but spend that much every month on crap they think is essential to modern life but is really just spending money on luxuries they like but don't actually need.

As for finding a used one - that's my recommendation especially if you really can't afford a good new one or are too f***ing cheap to sacrifice any of the other "essentials" (read: luxuries) you pi** away money on. Yea, look on Craig list, but also look around at yard sales, bulletin boards where cyclists or outdoors oriented people hang out. People buy these things and invariably sell them after about 5-6 years in good used condition for very cheap. BTDT.

Please note: my tirade about personal budgeting above is not directed at OP, please don't take offense. It's just a pet peeve of mine and I'm using the comment made above that implies that $250 for a bike trailer is an excessive amount as a launching pad for my little rant!