can't add any new input that hasn't already been brought up, but if you have the means (e.g., enough finances, enough space in your apt/house), the perfect solution is to do both. get that dawes for cheap, and that'll get you out on the road riding right away. but also start looking for that classic frame you want to build up as a project. it'll take longer and cost more money eventually, but like you said, you only spend a bit at a time. this way you get to ride right away and you get the rewarding experience of building your own. best of both worlds.