I subscribe to /r/NoContract/ so I have a pretty good idea what's out there.
Visible+ is a comparable pre-paid plan, it's $29/mo but that's a teaser rate and to keep it past one year, you'd have to port out and port back in for whatever deal they have in one year. The normal price is $35/mo, so I'm beating that. (Visible would also mean managing 4 separate accounts since they have no multi-line plans.)
Total Wireless is a bit cheaper ($26/mo) but I keep reading terrifying customer service issues with them including most recently losing number during the porting process.
Aside, I briefly used US Mobile earlier this year to port a VoIP line to Google Voice (GV will only port-in mobile numbers). US Mobile's customer service is exceptional. Would recommend them heartily for pre-paid service. But they don't currently beat what I'm getting from Verizon post-paid. I'd consider them if I can't keep my loyalty discounts next year.