Not a waste of money if parts are cheap, my replacement tank was £25 on eBay (couple of small dents, couloir is ok), used original injectors and sourced a fuel rail and rigid plastic connecting tube for a further £25.
If the out of tank pump was such a good idea, Suzuki would've kept that set up and it certainly wouldn't be needing an extra (third party) low pressure pump fitted, after stripping that 'out of tank pump' assembly down and Suzuki quoting me £60 for just the filter and 2weeks and extortionate prices for the other consumables inside the pump assembly, I decided to look into alternative fixes and decided that the 'in tank' set up was cheaper (for me) and better in the long run, much simpler and would eliminate, known problems, like vapour lock, expensive filter costs, awkward fuel lines, regulator issues, engine bay clutter the need to fit another pump and not to mention that awful fuel tap/petrol level sender unit in the tank, which is prone to filter gauge blockage and a pain in the neck to shut off (why on earth did Suzuki not cut a slot or leave a protrusion on it?) causing its own problems.
I'm not saying that keeping the old set up is a bad thing but I'd say that other solutions, shouldn't be disregarded or not considered, especially when a particular model changes a set up, like the fuel system delivery.
