I think, get a Nuna and then when no 2 comes along get another second hand travel system. I have an oyster 3 travel system I got with my first, it's kinda heavy but my in-laws bought it for us new so I wasn't about to think of getting anything else 😂 anyway we used it all the way til toddler was over 2 then bought a lightweight stroller from John Lewis, so when no 2 came along we could just use the oyster 3 again for newborn. But if you hate the egg 2 and bought it secondhand anyway, I'd switch now. I'd try the big seat first just in case you get used to it though.
Not sure what model of nuna it is but I'd say having a travel system + a small compact buggy that folds as one piece is almost essential as baby grows. Most mums of tots I know (and me) have ended up with 2. Lots of benefits to a small compact one like holidays (most airlines will include buggy when traveling with under 2yo but will charge if it folds as two pieces), taxis which may not have room for larger pram. In general as they get bigger having a big pram becomes a faff. Buuuut the travel system is sooo handy in the newborn days so if you have it already I'd hang onto it. There are some good second hand bargains on marketplace and vinted :)
I changed to a stroller at 6m x
@Jess we actually got the egg secondhand so I’m not expecting masses for it but I didn’t shed out over a grand either so I’m not too mad. I’m just sick of the bloody thing taking up space in the car.😂