Thanks everyone for the advice and great points. Obviously it takes the hours it takes, although with some prior lessons and theory covered already i'm hoping to stay under 50 hours.
As expected there is universal pushback against paying any hefty money upfront. It makes sense, both from potential flight school bankruptcy risk and schools potentially being tempted to use lump sums disproportionately to service fixed costs and not actual training costs.
It begs the question that, despite being rejected by experienced aviators, are schools "getting away with" charging lump sum advanced payments? If so, why are bad practises tolerated, is it just newbies not knowing any better? Or is it a case that by quoting a "package" they aren't expecting thousands in one go anyway?
Cheers!