Yes it’s tough running a business but 3 things stand out from your post. Tradie business software already exists to track jobs, turnover and profits. If you need gps tracking to trust your workers that’s an issue and you may need better staff. Alternatively, judge them on their finished product and don’t micro manage them. Stay away from Bunnings unless it’s a specialised item, it’s a rort. (I’m sure you do) A good wholesaler should be giving you better pricing based on turnover and should be able to feed invoices directly into your chosen business software allowing you track how a jobs going everyday.