Larger, inexpensive, framed mirrors for home decor can be found at any building supply store such as Lowes or The Home Depot. You might also try stores such as Big Lots or Walmart. I have purchsed several larger sized mirrors for bath and bedrooms at Lowes which were very satisfactory.
The bestplace to find mirrors such as this is Lowe's and Home Depot or similar places. I found a beautiful mirror at Lowe's. You will be surprised at how nice they are. Try second hand stores too such as Goodwill or Salvation Army. Also, try consignment shops or estate sales.
Lowes and Home Depot have framed mirrors and they are not expensive and very well made. They can also be found at Walmart, Target and Kmart. Most furniture stores carry a large selection of mirrors in all varieties. You can also visit many thrift stores and Good Will places and find alot of great buys on mirrors too.