Baffle Removal

Have been trying to remove baffles from my stock exhaust in the same way of the video link on here where they use two hole saws to remove the baffle. Does anyone know where I can get decent hole saws to do it? Ive wasted nearly £60 on 4 hole saws that are supposed to be for metal but after scratching the surface of the end plate for a few seconds have less teeth than a chicken. Soon be cheaper to add new pipes.

I just used a 3 Inch Bi-Metal B&Q one, PTX I think the make was? it cut through it in no time, Can't remember how much it cost but didn't seem expensive.

Have got them out. Brother in law had some bosch ones and they went like a knife through butter. Bike sounds a lot better know.