I just ordered a dozen new M10x1.5 - 60mm flange bolts in grade 10.9 (5mm longer than OE) and a dozen flange nuts from Bolt Depot. I found their prices significantly cheaper than Fastenal that I previously referenced. I needed a couple M10 130mm bolts for my junkyard trailer hitch and that led me to needing to place an order.
The bolts are $0.93 and the nuts are $0.21. Shipping is reasonable - I had several other things and the shipping was $6.80 total.
https://www.boltdepot.com/Product-De...?product=17513
If you're feeling guilty about re-using your $20 BMW bolts, this would be a much more economical alternative.
AM.