I did mine just pre covid with timber softwood doors. They were £250 unfinished, same thing is £450 now post covid and probably made from worse quality wood.
Needed to prime and paint them. Say £50 for primer and good quality paint.
Need to reframe the door. Say £50 of timber (plus side is you can make them fit odd sizes easily)
Hinges, locks, bolts, fixings etc not cheap £100
So I’d say at least £650 for basic timber doors, if you value your time as free. If you want no maintenance durable hardwood or accoya doors then god alone knows what that’d cost now.
They’re a ball ache to paint properly as you really need to do it before hanging them. Then a weekend of work to fit.
If I was doing it again I’d bite someones hand off to fit a roller door for £1000