The checkout price is only one part of cost. A cheaper item can wear out faster, require expensive consumables or demand more maintenance.
Calculate cost over useful life
If a $20 item must be replaced three times while a $45 alternative lasts the same period, the cheaper option is not actually cheaper.
Consumables change the math
Filters, cartridges, batteries and proprietary accessories can cost more than the device over several years.
Repairability has value
Available spare parts, standard fittings and a usable warranty can matter more than a small difference in purchase price.
Expensive does not automatically mean better
A high price is not proof of quality. Compare durability, features and ownership cost rather than brand prestige alone.
Bottom line
Keep the solution simple: start with the most likely cause, change one factor at a time, and observe the result. That makes it much easier to identify what actually works in your situation.