funny enough i have same goal, and same smith lvl atm--80, and similar amount of money to waste- i mean invest, and then certainly, same decision to make. rofl. my choice is: go for it! 11m is not hard to make. but before doing that, personally i will raise my combat to over 100 so that i can mine runite safely ( i have 85 mining btw which helps a lot). also i suggest choosing mith and steel bars than iron. it may cost a little more (1-2m more i guess), but a lot faster (50 or 100% faster xp) than iron. Aslo you should just alch pl8 for mage xp. dont waste time selling. good luck