Me as a beginner I`m learning the hard way after buying cheap stuff on Marshall`s (gloves, socks...)
It`s hard to accept but ski is not a few bucks type of sport, you will have to invest some money. Don`t wait you to get in trouble before investing in some good/right gear. Don`t wait your hands to be freezing in a windy day to go buy good quality gloves, don`t wait your foot to start hurting before investing in good boots bought in a respectable ski shop.
helmet, good boots, good quality gloves... you will end up spending the money on all that, if you don`t do it the first time you will be end up spending more money since you will have cheap gear that you won`t use anymore...
helmets: there are many brands that make good quality helmets, you can find them on sale on sierra outlets or even overstock (bought mine and my wife`s smith helmet at overstock)
gloves: hestra makes good quality gloves, they cost more but are good quality and will keep your hands warm. people will say that $20 gloves from costco will be enough and I believe it will for some people, but that`s not true for most of the people, if you have cold hands you need to invest on good quality gloves.
boots: go try them on at your local ski shops, there are good people working on the shops, they are skiers and will know how to help you finding a good fit for you, there isn`t much difference between brands nordica, head, lange, tecnica, solomom they all make good quality boots. you will end up making your call based on fit and comfort.
I also have something I use as a rule when I`m buying stuff... the most expensive doesn`t really mean the best, but also don`t go all the way down to the cheapest gear you can find on walmart or marshall`s. Columbia, North Face, and others have good quality pants/jackets for a good price. You don`t need to buy high end arcteryx or mammut... there are good gear out there for good price
my examples are:
1 - cheap gloves on marshall`s... freezing hands on a windy day. ended up buying hestra gloves and now there are two pairs of $20 gloves in the closet.
2 - lease package included with my classes, so I was taking the skis/boots/poles to the mountain every weekend. After all the mess inside my car, and scratches all over it I bought ski racks... spent the same amount of money, but now have scratches in my car...
3 - last season turbine pants for my wife... a little snug but good enough... ended up having to buy another ski pants since the first one wouldn`t fit the way it should over the boots