$50-80 bucks for a finish plus sandblasting is a very good deal. I pay much, much more for the finishes on my customers' frames at Spectrum Powderworks, but given the quality of the finish, the fact that they can airspray on logos, do amazing effects and colors and complex graphics, etc....it is very much worth it.

Powdercoating is a great durable finish, but can go on fairly thickly, and if the bike has lugs, you can lose the definition of the lugs at their shorelines. Some people don't mind, but something to be aware of. Also powdercoating is generally less expensive than wet paint, especially if you don't want anything beyond a basic single color finish. Most powdercoaters can't or won't do multiple colors or masking. Whomever you find to powdercoat the bike, make sure they are intimately familiar with finishing bicycles, as you can really gunk up vital little areas (like bottle bosses or derailleur hangers) with powder, and tapping them out is another expense.

I would recommend sandblasting over chemical strip, as chemical strips can be nasty, and time consuming.