Framework for product validation: How much spend is enough to rule out a "Product Issue" vs "Creative Issue"?

Hey everyone,

I’m launching a new specialized store targeting Canada/US. I’m currently finalizing my product selection and planning my testing phase.

Context:

• Product Price Point: $80 - $100 range (High ticket)

• Target CPA: ~$25-$30

• Traffic Source: Meta Ads (static + video)

My Dilemma:

I have a limited budget for testing and want to be as lean as possible. My fear is killing a winning product too early because of bad creatives, OR burning cash on a loser product thinking "I just need to optimize the ads."

Questions for the veterans:

1. The "Kill" Criteria: For a product in this price range, what is your hard stop for ad spend? (e.g., 3x Target CPA with no sales?)

2. Product vs. Creative: If I have a high CTR (>1.5%) but low conversion, do you immediately blame the landing page/price, or do you keep testing new ad angles?

3. Timeframe: Is a 7-day test window sufficient for Meta's current algorithm to stabilize, or do I need to commit to 14 days or even longer?

Any insights or "rules of thumb" you use for your own stores would be massively appreciated. Thanks!