Are there any relatively cheap 3g/4g/LTE modules out there?I cant seem to find any.
Depends what you mean by cheap, but IIRC, the Photon (or is Particle?) folks might have something. Probably others as well.
Siemens (now Gemalto) do a range of M2M modules, the costs might be too high though (~$30 for the EHS6 for example):
http://www.acte-uk.com/manufactures/gemalto/embedded-modules/
Mark.