Yes - technology can be a problem, and so can equipment. Different suppliers offer the "same" equipment but at different prices, or that's how it seems until you actually get your hands on the kit. If you are not a physicist, or have only very little experience, can I recommend that you shop with care. Biology & Chemistry have a high turnover of basic chemicals and use simple glassware on many experiments; Physics uses expensive equipment which can last 20-30 years but with low running costs. As an example: power supplies (12V ac /dc). Some will only allow discrete voltage steps, others are totally variable. Some will allow a couple of amps, some will allow 10 amps. Some will have fuses (perhaps in "odd" sizes), others have resettable circuit breakers. Some give smooth dc, others are just full-wave rectified. Prices can vary from under £50 to over £250. Knowing what you will do with them, and how many classes will be using them at the same time, will help you to make the "best" purchasing decision, but, of course, the criteria will change over time. Do you want to buy cheap equipment and replace it every 5 years with "up-to-date" stuff, or buy expensive stuff which might seem "dated" in 15 years time? In my opinion, a good physics teacher enjoys making things work. Recently I worked in a school where motor kits were purchased at low cost BUT had never been made to work in 10 years. To me, that was a challenge, and eventually, with a lot of effort, I was able to demonstrate to the pupils how a dc motor works. Had the school spent 3 times the amount, pupils would have made their own kits function easily . If you are doing CIE, are you abroad? That has ramifications for suppliers, in terms of who you can use and the cost of transportation/warranty. Sorry if I've raised more questions than I've answered, but with over 35 years experience, I can assure you that what you are about to do has to be thought about quite carefully. For example, for any given experiment you might want 1 set (to demonstrate) or N/n (where N=number of pupils per class & n=group size for that piece of practical work) BUT you could get away with less than N/n by arranging your approach to practical in a different manner. If you are doing "written alternative to practical work", you might decide to have demos only (but the kids will not gain as much). I COULD go on much longer, but I really need to know more about your situation.