I'm new to folding bikes and just found a Bike Friday on Craig's list that's in my price range. The bike is a few states away (shipping is only $25) so I won't get to test ride it before buying. The tube length on the bike is 48 cm. I'm 5' 7" and usually ride a 52 cm frame (top tube measurement). Should i bite on the bike? I'm assuming I can add a longer stem. Just wondering if I should hold out for something closer to the frame size I ride now? I'm planning on doing some urban bike touring in Portland, Seattle, and Vancouver in a few weeks and wanted to pick up a decent bike before then, but didn't want to spend more than $300 and would like to get a bike I can resell if it turns out not to be ideal for me. Thanks for the help.