Being in a similar situation a few months ago (I had a $850 use-it-or-lose-it credit), I went with the trek 7.2 for ~$550, and got a trailer to go with it (~$220 I think?). I also tested out the 7.3, but I didn't notice enough of a difference to make it worthwhile for me. I'm hardly a bike expert though, since I've only been biking again since August, so YMMV :). Although a used bike might be best in most circumstances, if you have a use-it-or-lose-it work benefit that you have no other use for, I don't think you should feel guilty about getting a new one. Though keep in mind these types of benefits typically count as taxable income, so even if you pay $600 and get $600 back from your employer, you'll still effectively be paying your marginal tax rate on the bike.