If you are going up or down stairs, I would recommend checking to see if you have a moving equipment type store that rents Escalera stair climbers. I used to use an appliance dolly that I got from Harbor Freight, which sufficed, for anything outside of going up stairs. I then found a moving equipment store that rented Escalera's for $35/day (bonus is that you won't have to store it when not in use).

If you're not going up any stairs, the appliance dolly from Harbor Freight is hard to beat with the 20% off coupon.