I would say that fiction-factory’s estimate of your pension lump some value to be on the high side.
Pension companies work out how much money they would need to pay out your annual pension. They do this for all in the pension scheme – that way they can work out whether there is enough money in the scheme to pay all liabilities.
To turn your annual pension into an amount of money that they are willing to pay you, they use something called a commutation rate. The pension company is free to assign any value it chooses to this rate, a low rate would be 10 and a high rate 20 (even where the pension is indexed linked and there are other benefits such as a spousal pension).
So a £1.5k/annum pension could have a total pension pot value of up to £30k, but a value of around £20k is more likely.