margie,

IF you do switch to a single GET THE DUAL carbs back from the shop.

If they are dual T4 Webbers or Dellorto's they are worth around $300 to $500 at a VW swap meet new kits are @$700+.

A T4 single webber carb kit cost is @250.

Look in a VW mag to get a price to compare what the shop is telling ypu the cost is going to be for a single webber kit.  The time to install one is about an hour to an 1.5 hours, labor to install shold be close to that figure.

You can sell the dual carbs to offset the cost for a new kit.

Robert