I've done this almost from the very beginning (back in the 90s) and always had very small mobile communications costs because I could easilly change providers and plans and even do things like use a local SIM card whilst abroad to avoid roaming costs.
I haven't financed a phone since 2008. I copped a fee for ending a 24 month contract a day early.
I just buy a cheap outright handset, flash a community ROM and avoid everything my telco offers past a $20 basic service. Handsets with community support go for years past what the manufacturers support.