If your needs are greater than a Pi but not at the level where you want to be buying professional server hardware, I can recommend checking if you or a family member still has a laptop they're not using anymore. Free hardware that would otherwise end up going to waste, and anything that had good performance in 2012 is still faster than a new Pi today. The older, the more likely it is to have replaceable RAM so you can stick in 16GB easily (older RAM types are also cheaper)