Yes you start with 900 to 1200 that’s $300 profit . Then you purchase again at 1300$ sourcing a $100 from elsewhere. To make$1600 so another $300 . So Total profit is 300+300 - 100
I agree with all your math other than the sourcing the $100 from somewhere else nostr:nevent1qqsvxkzwvcrn36653jyf2eukanz3t8z5tz9jyvzm2xv6m43875lc0ycpzamhxue69uhhyetvv9ujumn0wd68ytnzv9hxgtczyqrgxrmvkkf9hkpvefvmm2zg7qzkvekl7prv2wpfvw5e0g35mfqv2qcyqqqqqqg66sdkm