There are two points to make about my Roberts that are relevant to the OP. Firstly, there are still some good steel bikes out there, Chas Roberts will even put one together for you, but the price is high for the really good ones, just as carbon or Ti bikes aren't cheap either. Or you can go down the self build road as I've done where you buy a good, possibly fantastic, quality frame for not a lot and build it up with either the original vintage components or newer kit. I've done both and the total cost is very much less than you'd imagine.
For example; the Roberts frame cost me £133, 8 speed Ergo shifters £30, Campag monoplanar brakes £30, wheels complete with cassette, tyres and tubes £70, mechs £25, chainset £25, bb £5, pedals £5 (car boot sale gems!), stem and bars £10 (car boot sale yet again), seatpost £20, saddle £10, odds and sods about another £30. Total cost under £400. Ok, you have to know what's what and how to put it all together but there's a wealth of information out there that'll get you sorted. Most of these parts were sourced either from
ebay or from the various cycling forums and I've rarely bought a bummer, especially from forum members.
The alternative is to go down the road that another forum member and my riding buddy, Rezillo, has followed. John bought a Guerciotti steel frame at a knock down price and has built it up with shiny new Shimano kit, Ultegra as I recall, and it looks as good as it rides. The steel frame gives a remarkably smooth ride but the bike as a whole does weigh more than his carbon Orbea Onix. I don't think the additional weight makes that much difference to the type of riding we do, but I'm sure the ride quality does. Mind you, the whole ensemble would be much improved if he'd used Campag rather than that far eastern stuff, but that's an argument we have every time we ride! Don't know how much the Guerciotti cost in total, but knowing John it's likely to have been good value.
Gordon