That £83 k quoted by Lisa includes statutory interest, which might be waived, or even already excluded in the agreement (it was in mine).
So my calcs would be ( and these are back of a fag packet calculations) --- to settle the whole thing:
Original debt £58,000
Fees (generally around 15%, so £8,700, plus Nominees fee and disbursements, usually around £2,000
At the three year mark, considering the reducing balance, statutory interest would come in at around £8,000
Total to settle = £76,700
At that three year mark (gratuity point) you will have paid in the best part of £45,820 (by your calcs) --- leaving £30,880 to clear.
At this point it can go one of three ways:
Either your IP will let you keep the gratuity and you carry on with the next 2 years payments --- difficult on a pension.
Or they take the gratuity and use it to hit that settlement figure and close the IVA early.
Or .... they let you keep the gratuity and you propose a Full and Final Settlement. This is a different animal to a settlement and is an offer to "pay up" the remaining agreed payments in a lump sum to close the IVA early --- in your case, at that stage, the creditors would be expecting a further 24 payments from you at £900 a month, so £21,600. This could be less if a review, based on your post service income brings the agreed payment down. But, on the £21,600, you could round it down to, say, £18k.
Clear as mud !?
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014
Visit my blog here : http://foggy.blogs.iva.co.uk/