Earlier quoted context omitted.
I've looked into it in the past and keep looking at atleast a £500 cost -usually more if you want O2, CO, CO2, H25 (I think those were the ones I decided I was interested in).... and _then_ there's the certification cost, so I really can't justify it (though I'd love to). My friends dad used to be a safety inspector duwnt' pit in the 70's and he's been trying to convince me to get an old Davy Lamp and to just pay att…
Alibaba's got them from about $150 single gas http://www.alibaba.com/product-detail/NEW-K60-handheld-0-200... $400 multi http://www.alibaba.com/product-detail/Portable-diffussion-ty...
Though I'm somewhat wary about buying potentially life critical systems from AliExpress -especially when I have no idea how I'd go about testing, never-mind certifying it :)