I'm a single parent for similar reasons to Booboo - my DS was planned then his 'dad' (I use the term loosely) decided he would rather be with someone else and fucked off with the OW when I was 17 weeks pregnant. He's never bothered to see DS and never voluntarily made a child maintenance payment, hence when DS was 2 months old I went to the CSA. Over the next 3 years I had to chase them fortnightly at my own expense and supply them with all ex's contact details including phone number, bank details, parent's address and his new address because they couldn't be arsed to do their own research. During this time my case was transferred to numerous offices, a variety of case workers and my case notes were lost at one point. I even resorted to writing to my MP three times to try and get things moving because my ex was cleverly using every trick in the book to avoid paying - working cash in hand, moving jobs, moving house, not answering letters and claiming he was bankrupt. Yep, I've heard it all. Still think we should sort a private agreement out amicably, HappyMumy? Eventually, the month before DS was 3, I received my first payment - of a whopping £6.25 per fortnight. Fuck me, that was worth fighting for, wasn't it? 
So, once my case is closed next year and I'm invited to re-apply, I have to pay £100 application fee (the higher amount because I work, albeit part time - so as Inertia rightly pointed out above, I'll be paying twice, once out of my taxes and the other via the fee). Then they fanny around taking another 3 years to sort out my case again only to give me the same £6.25 per fortnight, which then has a percentage of up to 12% fee deducted from it to help pay for the amazing service I receive. So with the fee deducted, instead of getting £12.50 a month, I'll get £11.00. Hardly worth it, is it?
So for me it won't be worth reapplying. Personally, I think it's partly their aim to discourage RP's from reapplying. The difficult or awkward cases won't bother to reapply as they know it's not worth their while, plus some new cases won't apply as they won't be able to afford the inital application fee (which of course falls to the resident parent to pay, not the non-compliant NRP, even though they have DC to feed, house and clothe and aren't receiving maintenance
). This means that the overall number of cases on the CSA's books will be reduced, and those that they do handle will be cases that are more likely to be sorted quickly, therefore increasing their success statistics. So once statistics are start to be released (probably just before the next general election, I reckon), for example they may state that 90% of applicants are receiving maintenance. However these figures won't be taking into account the large number of RP's who couldn't/didn't reapply, but the figures will look good to the electorate, many of whom dislike single parents due to the media stereotypes of us being benefit-claiming, plasma-buying chavs whose biggest ambition is to appear on Jeremy Kyle with our delinquent children. And we probably don't know who the dad is, anyway.
The whole scheme has not been thought through. Feckless NRP's will be able to avoid their responsibilities and get away without paying maintenance even more than they already do, which in turn leaves children at higher than ever risk of poverty.
For a country/government that is supposed to put the family and children first, at best this is an embarrassment and at worst, as disaster.