On buggies, I've done a bit of research and I think there are basically 3 main variables:
- size and weight
- wheel size
- ease of folding
It's like one of those triangles (fast, cheap, correct) where you really want all 3 but realistically can only have 2. So something light and small that folds easily into the car boot of a city car will have tiny wheels that jam on anything except smooth flat tarmac. And something with big wheels for rough terrain will either weigh a ton, be extremely bulky, or be a total pain to fold (potentially all of the above).
There are loads of Bugaboo Chameleons and Bees on Facebook marketplace for a very good price - often under £200. There are also Uppababy models on Marketplace but a bit more expensive - the Vista might be about £350. I've also looked for the Babyzen yoyo second hand, but people are cagey about the price and tend to sell the newborn bassinet separately - for about £200! So I think that one's a no-go on a budget - but if you did buy new, you might make a lot of money back.
The other thing about the big travel systems is there are compatible car seats that will clip onto the chassis. I haven't looked into this much because I don't think it's something that I'd use much after the first few weeks.