Haven't read any of the comments as I'm supposed to be working - but my thoughts:
I left school at 18 and got an OK job. Bought a house at 21, and had a fab fun time socialising in my 20s and early 30s, Was with my first BF for ten years then suddenly single at 28. Got a better job commuting 30 miles a day in my early 30s. had a few relationships but nothing serious. Always wanted a family and kids 'one day' but did enjoy the single life! Had a seriously good career between early 30s and early 40s, great money, lifestyle and bonuses. Met a chap in my mid 30s, married late 30s, started trying for children.
I always thought having kids was easy until you were in your 40s, was on the pill all my life, suddenly not so easy. Both of us had nice houses and were financially secure so we were in a great position to have a family and not have to worry about moving up or childcare (my job wasn't one that would be easy to work around kids so I planned to be a SAHM) - but after lots of trying and lots of tests, at 42 I found I was peri-menopausal and our one attempt at IVF stopped halfway through as it didn't stimulate any egg production.
We were lucky - had donor egg treatment abroad and had wonderful boy/girl twins, but I was definitely the oldest at primary school pick up. DD used to laugh that some of her friends grannies were younger than me! Now they are at secondary school and it's not an issue. We are all fit and well and go for bike rides and went skiing and they have ponies etc - so I don't think being older parents is a big deal, although we will perhaps miss out on seeing our grandchildren/GGCs etc.... But financially we have had an easy time of it, we aren't scrimping to buy a bigger house, or worrying that I should do more than my low paid, part time/flexible hours job.
So I agree - it is catch 22! Financially I'd say wait, but you can't be sure about nature. When I was looking at donor eggs they said the younger you are, the easier it is to conceive. Over 35s are considered too old to donate eggs!
My friend got pregnant quite young (married, but unplanned) and her MIL said 'there is never a right time'. I think that's true. (It all worked out well for them). You will cope whenever it happens. But someone else told me - either do it young then have your life afterwards, or sort yourself out first and have them later'. Again - no idea if that's true but as someone who went for the 'later' I can thoroughly recommend it....
Good luck!