I am 15 and have a massive itch to build another bike. How do I mitigate these habits?

For context, I've been working at McDonalds for the past 8-9 months and have saved 8000 dollars in my bank account.

In my freetime I love to build bikes, I've build 3 bikes now, and usually it costs me less each time, so the first time in 2025 was like 800 AUD, then 500 AUD at the start of this year, then 250 AUD just recently. I don't spend money anywhere else.

Only issue is, I've also just got a job at a bike shop, where everything is 50-70% off, and it is VERY tempting to pick up some gear and build a bike.

But I shouldn't keep building bikes because, you know I should be saving. I have made a spreadsheet which tracks my financials. So it includes all my paychecks, money spent, money spent % and required amount for the month.

This year I have spent 17% of my income, and I'm trying to get it below 15% and eventually under 10% by the time I'm 17.

How do I achieve this goal by reducing the urge to build another unnecessary bike?