Recommendations for website filesizes re mobile data rates?

Are there any recommended guidelines for how much a data a mobile-friendly website should consume during casual browsing?

For desktop browsing, data consumption is not so much of an issue, so long as load times are good. However, many mobile users may be on a fixed data plan, and will avoid visiting websites known to gobble up their data.

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(Example scenario edited out, as it seems to have distracted from the actual question.)