maybe read through the homemade extracycle thread and try making one with an extra bike? the initial effort is more time than money. if you like it go for something better. if not put the bike back together as it was and you're not out much.

for me it's not a serious want so i'm just making one to see if i can. the cost has been pretty minimal. it's looking like i'm going to top out at about $150. if i get more serious about wanting a better one, the thing i spent the most on (the bag idea) hopefully i can transfer over to a more serious effort.