WEll, sometimes you have to decide whats worth the hassle . If you can get that little extra from them, great!!! The worst they can say is no! But if you are prepared to pay it now, talk to them and say "look i'll pay you if you agree to report it this way and put that intention if writting". If they say yes, then tell them as soon as you have confirmation of that agreement, you will send payment. If they say no, but the debt is still in SOL and you are willing ot pay, then you may have to take the lump and pay it. A "paid Collection" looks better than an "open collection".
Really by running off and reporting to CRA's , collection agencies are throwing away a great barganning tool. Once you put a mark on my Credit report me, what motive do I have to pay right away or pay the full amount??? Why not hold out for a settlement, my credit is already blemished anyway.
If you already reported me, work with me a little, and you may get paid more and possibly sooner than you might otherwise. CA's do have the authority and ability to make these kind of deals, if they choose to.