JMO but those sound like reasonable preventive maintenance and repair costs and Odysseys are generally really great vehicles. I don't agree with your mechanic's receptionists assessment.
Going to a 4WD like Pilot actually will cost you more in maintenance and gas costs. 4WDS suck the dollars in maintenance and tires!!! Why pay more for a newer Odyssey if yours is reasonably sufficient? We have a Pilot and have had 3 Odysseys. Honestly it doesn't sound like a lemon and mini vans are awesome for toting kids and random things around even if not routine. I'd keep it for 2 years and revisit then. My two cents!