To start with, there are two different types of face powder - loose and compact - which offer slightly different results. Loose powder is often a lighter alternative and ensures an airbrushed finish on skin, allowing you to lightly dust over the surface and fix makeup into place. However, it can be messy and it's not practical for using outside of your bathroom. Compact powders have been compressed to provide a 'solid' pan from which you can brush over and remove a little product; these are much more practical if you're concerned with mess and also make it super easy to touch-up on the go. The key is to avoid using the puffs and foam applicators that come with the compacts, as these can overload the skin and leave you looking way too powdery; invest in a mini brush for on-the-go instead.
So, do you need to spend a fortune to get a good product? Essentially all powders are made up of pretty much the same thing (mainly talc,) but the more expensive products tend to be more finely milled (or ground) for a super fine powder. The finer the powder, the more natural it looks on the skin and less likely it is to end up feeling cakey. Most of the time you'll be parting with additional cash simply for the pleasure of buying into a brand name and the beautiful package that holds it - rather than the product formulation itself. Unlike foundations and lipsticks (which tend to use more advanced technology as the price point increases to provide comfort and a long-lasting formula,) essentially every powder formula is made of very similar ingredients; there's only so much additional performance you can get from a basic formula, so it's good to be cautious.
However, when it comes to compact powders I have noticed that the cheaper brands have a much higher tendency to break and smash - meaning you have to throw them away and part with yet more cash for a replacement. I very rarely get through an entire pan of Max Factor, Rimmel or Collection powder, but my Chanel, Charlotte Tilbury and YSL compacts are still going strong. You may be buying into a beautiful brand, but that beautiful pack also helps protect the product inside and ensure you can use every last bit. Your purchase decision has to take this into account - is it worth spending £20.00 now rather than having to replace a £4.00 product five times?
If you're a little worried about powders initially but want to give them a go, investing in a more expensive product may help to ease you in and provide confidence. (I would definitely recommend visiting a makeup counter for tips on application.) However, budget buys and mass market brands tend to offer equally as good products if you know how to use them; using a light powder brush is key to only picking up the amount you want and not overloading the face. (Use sponge applicators at your peril!) I have a combination of brands, price points and textures in my collection, but I wouldn't say there's a huge amount of difference in performance. Essentially, the decision is yours - are you more concerned with a pretty pack that you can chuck in your handbag, or would you rather spend a few quid and splurge the rest on a new necklace?
Are you a fan of face powder? Do you prefer budget buys or more expensive alternatives?