I have a very accurate picture of what my boat costs, because I keep everything I spend on her in Quicken (I charge virtually everything, then pay it off at the end of the month, so I have every thing I buy in the system)
Last year I spent $21,000 all-up on Gigabite. The slip and insurance costs were slightly more than half of that. Fuel was a bit over $3,000. We did not run much last year due to the storms (there was a 2+ month period where we could not GET diesel here), but the price per gallon of fuel was MUCH higher than it has been in previous years.
The year before was an outlier, in that I had an $8,000 "surprise" in the form of new exhaust collectors..... but leaving that off, the total bill was a bit higher, mostly due to some retrofitting (all new hoses) and more running time (fuel expense). Again, insurance and slip costs were about $11k.
Fuel, since 2003, has roughly doubled in terms of annual expense, but in 2003 we ran more hours than in '04 or '05. The actual price per gallon is up about 130% since '03, and it does show up in the numbers.
In the years since I've owned Gig there has never been a year where there has not been some form of a "surprise." They all end up bettering the boat significantly (e.g. last year I stuck in Floscans - that was a $2500 set of hardware), but if you don't expect $5-10k per year in "surprises" on a 45 footer you're asking for it, because when (not if!) you get one of those you're going to be trying to figure out how to pay for it.