30k Boat costs

[volvopaul]

46k for a '89 330 may be good value (I dont see it but I'll take it as market value, good is another opinion) but if the OP could find one for 30k I dare say there is a very good reason to look closely.

That one has 2003 engines so it’s lost it’s smokey 41s which helps the sale and hopefully has the later hydraulic gearboxes .

 

[Silvercloud]

One essential item you will require as a single 27 year old on your boat is a LARGE double berth for "entertaning" your guests

 

[Megs20Burt!]

The 10% annual cost thing is optimistic for your price range and for what you want to do.
Biggest expense will be a mooring (For a pontoon type mooring that will be £4K plus for an 8mtr boat plus any service charge)
For motor boats, going at speed gets expensive. Depending on fuel type, availability of petrol can be problematic in some areas.
Dont want to put you off but have you thought about a canal boat or a Norfolk broads type boat rather then a traditional motor boat?

The 10% thing is an urban myth, watch this...

 

[Sticky Fingers]

It's not 10% of what you paid for it. It's 10% of what it would cost to buy a new one today...