A good ultra-short throw 4K laser projector replaces your main TV and should easily last seven to ten years. Buying cheap usually means poor contrast, weak brightness, and loud fan noise, so it pays to get a solid unit the first time around.
Projector makers roll out new flagships in late summer, which means last year's top-tier models drop significantly in price by November. Tracking Black Friday sales lets you scoop up previous-gen hardware with nearly identical specs for hundreds less.
The 18-month 0% interest window is a strict deadline, not free money. Pay off the full balance before those 18 months end, or interest kicks in on whatever balance is left on the account.