Are service costs for a 348 the same as for a 355?
Here is a price list from a well respected mechanic in the LA area... http://www.eugeniosferrariservice.com/ 30,000 mile (MAJOR) Service for 308's, 328's, Mondial 3.2's & QV's = $2995.00 (348's are $3995.00, Mondial t's are $4995.00, and F355's are $5575.00 due to parts cost, engine removal, etc.)
Generally the 355 service costs are higher. One more valve per cylinder, and the fact that the newer car owner has (perceived) wealth helps drive these differences. The water pump on a 355 is not cam belt driven, and is easily accessible / removeable so they should be cheaper for that item. BT