Montgomery once bought four collectible plaster plaques for $15 and resold them on eBay for $700.
"That was probably the best bargain I ever found," she says. If she hadn't known their value, she probably wouldn't have bought them.
Montgomery says she looks for name-brand clothing, especially her personal favorites, or those that she often wears.
When it comes to furniture, she searches for pieces made of wood and with dovetail drawers. Dovetail construction uses notches to secure the front of the drawer to the sides instead of staples or nails.
A good way to learn about quality furniture is to visit some of the higher-end stores and examine how their pieces are made, Montgomery says.