i burn out home shredders once every 2 years, recently i started to take a piece of paper, drip 1tsp of olive oil on it and send it through the shredder, so far this shredder from newegg (i think it's a fucking rosewill) has lasted 4 years.
i just get whatever 50$ monstrosity is on sale for 20bucks at either staples/office max etc. as long as it can shred 1 envelope full of spam and cross-cuts, it fits the bill.
usually if it says credit card/ cd shredder, it's pretty powerful. the gears are all plastic btw, that's why they burn out, they just melt over time, ha. (i'm sure the office type shredders are all metal, but who wants to pay 180$ for that)