I've built a few prototypes etc... for Ford's B&P when I was at Team Detroit and there was some semi involved business logic. Most of these just a few years ago were build in Flash

, I was prototyping full HTML5 and CSS3 (keep the transitions and taking advantage of some modern browser features and mobile/tablet) B&P but due to the support of IE8 there still needed to be a Flash fallback. With that said this isn't exactly a trivial task but can be done easier with using a JS MV* framework.
Flash was used mostly for RIA or SPA (buzzwords for web apps that don't require refreshing) since JavaScript in IE6-8 was pretty lousy and lacked most of the features of modern browsers. If you don't need to support IE8, or 9, a B&P for something basic could be trivialized building it with Backbone, Ember or even building this with a MEAN stack but that's a tad overkill IMHO.
My personal experience, I'd "HIGHLY" suggest you architect/wireframe the entire B&P experience
and design each step (Model | Engine | Color etc...). Also don't forget to gather all the correct image assets; for example all the color options of exterior, different engine models and any others that will be part of the B&P. These are the steps that will allow a developer to knock this out a tad smoother.
Far as maintenance like adding new ATV's, that would be easy to add in with a lightweight CMS or for budget sake a simple JSON config file that had each ATV stored. It would be rather silly and bad business for someone to hold you hostage when adding a new ATV, but that's just me. Solid hosting say though Mediatemple is $20 a month (cheaper if yearly) and it's super easy to maintain domain name ($12 a year if you go MT). Buying a SSL and maintaining it though a solid host is cake as well, verification will be the hardest part.
Far as freelancers cost you have to factor in 1099 and expect a small premium to cover their taxes. I wouldn't hire a local shop for the sake of local or some offshore hack company, find someone who has experience with B&P's or similar small web apps. Make sure they have experience using lightweight JS MV* frameworks or expect a spaghetti mess; memory leaks, errors and people able to exploit the client side especially with JS.
Best of luck and if you have any questions don't hesitate to ask!