Tue Sep 15, 2015 3:46 am by Packbat
Like, suppose it costs $1,000,000 to design an engine normally. (I'm 100% making up this number, btw.) If you're designing a mechanical fuel injection engine in 1968, maybe that's how much the engineering costs are. Engineering costs aren't a part of total costs - total costs is per-unit, engineering costs are per-design. If you build 100 engines, that's $10,000 per engine, but if you build 1,000,000 engines, it's $1 per engine.
If you're designing it in 1967, you have an additional line item in the engineering cost which is for getting that technology early. There would be a limit to how early it would be available - maybe 10-15 years before the default unlock date? - but if you're within that window, the option shows up with maybe some kind of highlighted background to say, "Yes, it's possible, but it will cost you." So in '67 that might be just another $100,000, but in earlier years it would be more - maybe $220,000 in '66, $360,000 in '65, and so forth, until to get it in 1957 you're paying millions.
But people do that for, say, race engines. And if they're doing it for a race engine then maybe they'll try a production model - after all, they've figured out how to make it work, so they might as well see if it pays off in production cars. (Which, in 1957, it kind of didn't, but hey - you try things and sometimes they work.) So giving the option in sandbox mode would give people a little more flexibility, which could make for more interesting competitions based on sandbox mode, frex.