Five Guys, In-N-Out and others have found that specializing in a fresh potato French fry can be a real draw, separating their operations from a lot of other competitors.  However, it isn’t that easy to do on a consistent basis and unless you can increase the selling price over your current offerings, it is not something I would recommend.  If you are purchasing frozen fries for 50¢ to 75¢ a pound (a pretty likely scenario) then even at 25 cents a pound for fresh, you’ll only come close to serving a fry that is similar in overall cost.  Be sure to factor in extra labor, finding a spot in the back of the house to store the potatoes (55 degrees Fahrenheit or so), waste, more oil consumption, etc. and it is not an easy conversion.  Lamb Weston actually has a worksheet that lets you plug in the figures to make an educated business decision on serving fresh versus frozen:http://www.lambweston.com/support/profit_calculators/fresh_vs_frozen_calculator.jsp

Can you charge more to offset the savings?  That’s the real decision.  For our tips on frying fresh Idaho potatoes go to this link:

http://foodservice.idahopotato.com/how_to/id-1

And, here is one of the most useful tools to purchase and post next to your fryer for staff to finish fry your potatoes to just the right desired color:

http://www.shop.potatopro.com/usda-french-fry-color-card-p-64.html