Budget EVA foam hip protectors typically last just 1-2 seasons before the foam starts to compress or break down, which means their protective qualities decrease over time. If you're only skiing a few days a season or trying hip protection for the first time, these can be a reasonable starting point without a big investment.
The trade-off is that you'll need to replace them more frequently, and you should inspect the foam before each season. If the pads feel permanently flattened, stiff, or cracked, they won't absorb impact the way they should. Also, after any major fall, check that the foam hasn't compressed unevenly.
For frequent skiers, older adults, or anyone with osteoporosis or previous injuries, spending more on higher-durability protectors with smart foams like D3O is usually the better call—you get reliable protection season after season, and the cost per year of use often works out about the same.