Cost depends on a number of factors - type of harp, number of strings, reputation of luthier.

There are basically two types of harps, Celtic or lever harps. They have lever's that sharp the strings, or pedal harps. Pedal harps have pedals that set the sharps and flats. Pedal harps are the really big harps you see in orchestras.

For a decent celtic floor harp price will typically range between $3,000 - $8,000 dollars depending on the number of strings, type of wood, degree of customization, and reputation of the luthier. Mine is costing $5,500 CDN.
The harp I'm getting is comparatively light weight. It's 54 inches tall at it's highest point, and weighs 24 -27 pounds, so it's pretty easy to move - it'll fit in my car with the back seats folded down.

Celtic lap harps are smaller and designed to be held in your lap. Good ones range from $1,700 - $5,000.

Pedal harps are an entirely different beast. They're way more expensive and heavier. The entry price point on a pedal harp is about 15,000 and they can go up to the hundred's of thousand dollars for really fancy custom jobs. I have a fairly plain but high quality full concert grand pedal harp that I paid $22,000 for. It weighs 100 lbs. I can't get it in my car, so if I want to move it I have to rent a van.

--splitimage