Five or more years ago, when roaming data cost 5UKP (8USD) per megabyte or a local SIM gave me an allowance of of 40MB per month I used to browse with images turned off. It was difficult then (every button icon is an image so you rely on them also having text alternatives) and I reckon it'd be almost impossible now.

And it's not only images that use up your allowance - it's all the other stuff that smartphones and tablets do without asking - checking for updates, syncing data, ...

Data is much cheaper now - at least in Europe - so I haven't tried supressing images for several years. But then I always use prepaid SIMs.