Like so often in life, you are faced with making a choice. The most expensive remedies are the creams (Canesten, Lamisil) and their manufacturers cover themselves by warning that you must guard against reinfection. They know perfectly well that, even if the infection is truly removed entirely, it is likely to re-appear because of the nearly certain presence of the spores in the patient's environment (footwear, etc.) - sales of creams are guaranteed, not least if the infection is only suppressed.
In order to suppress the symptoms then, while I don't know the cost of sprays, the cheapest means by far is the application of vinegar (I found a contact lens fluid bottle very useful) at perhaps £2 a year. The vinegar is also dead easy to apply immediately after washing and drying, between, under and around the toes.
If you want to eliminate the infection you will have to take serious measures. Replacing socks and shoes need not be prohibitive - I replace my good shoes and day to day ones (work & leisure) with brand new ones at between £15 and £25 a pair. Sandals are available at similar or lower costs. In other words, the whole lot can be had at less than £100. How many tubes, tubs or spray cans of non-vinegar treatment does that equate to ? Alternatively, how many packs of cigarettes, pints of beer or other alcohol, take-aways and/or ready-made meals instead of from-basics, etc., etc. would someone have to forego to save this amount ? I really cannot think people genuinely cannot afford to replace their footwear - if they really want to. They may put it at the bottom of their priority list, and that is their choice.
If you want to try to eliminate the infection, then you will need to continue the treatment past suppressing the symptoms and until the skin has completely renewed itself - if I am not mistaken then that is some four weeks. At that point you would replace socks and shoes.
The other alternative is to simply keep applying the treatment whenever the symptoms reappear, probably lifelong.