Worth paying the 3,300 to get a lower rate?

enconalager

Hi there
Great forum , have learnt a great deal .
My current mortgage rate is 2.89% fixed for another 2 years (5 year fixed) .
I was looking to fix for 10 years at 2.49% (with the same lender I am with now - HSBC) , to change now will incur a 3,300 charge .
The current mortgage is 148k - can anyone advise how much I will save on the actual figure ? My concern is that interest rates are going to go up in the next year(have seen credit card lenders put their interest rates to track the Bank Of England base rate) - I have the fee in cash , so that will not be added to the mortgage .
Rough maths worked out I would 'save' around 3k over the 10 years as the monthly figure would drop by about 30 quid - so that would balance the upfront fee , but how much would I save on main figure ? 0.40%
There is no fee to arrange the new mortgage - when I asked the question to the HSBC advisor , they replied they couldn't provide that figure .
TIA