Hi Jim.
The first thing to do is to import your aircraft into the EU........if you are relocating here, and have owned your aircraft for a while, then you can get a dispensation from HM Customs and won't have to pay any import tax (it's 17.5% in the UK). It is important to do this or you may be impounded when travelling.
If you only want to keep it here for 6 months then a temporary job can be done....again it's important to actually do some paperwork and remember that all of the EU counts as one "country" for this sort of thing. You can't keep it in the UK for 6 months, then Ireland for 6 months.......
Fuel prices are high but they have been getting pretty scary in the US recently. You are looking at $8 to $9 a US gallon including taxes. If you are travelling "overseas" you can claim back the taxes (17.5% VAT and around £1 per usg duty) - this includes flying to the Channel Islands or mainland Europe and brings the cost down to around $6 per usg.
You will have to pay for hangarage/parking and each, and every, landing. Charges will vary according to where you are based and covered parking may be difficult to find.
Insurance shouldn't be too bad compared to US rates - our underwriters take a more informed view. Make sure that you are covered for the dreaded EC785/2004.....you will need to carry 7M SDRs of liability (about $10M) for a Baron.
Finally, don't forget Eurocontrol. Flying IFR in an aircraft over 2 metric tonnes incurs a charge. Within the UK expect to pay around $40 per 100nm. Most other countries within the EU charge a little less.
PM me if you need to .....I run a worldwide ferry operation
