Replacement tyres F10 528i MSport

[TSS]

hi all,I am running on the original runflats Dunlop SP sport max 275/40/18 ( rear) and 245/45/18 (Front).I hit a pothole recently and there is a small bulge in the tyre wall ( driver side). Thought of replacing them. Any other recommended runflats? I have no complaints on these original Dunlop tyres . Need some opinions on other brands like Michelin, Bridestone. Or Continental.Where is the best place with good bargain for these tyres