Of itself the mechanic of free advantages doesn't do that much game-wise except limit technology cost bloat. Lower techs will simply apply the same advantages to the components.
To have a better representative effect of increased TL we should also include a further mechanic (which our current list of advantages may not cover)
As many advantages can be applied to a technology as the ship's building TL - the component TL. No more than 2 of any one advantage may be applied.
We may want to keep some cost increase per advantage say 10%, (edit: 5% per my other post, budget is -10%/use) so that there is some recognizable cost difference when building ships though. While saying the high tech shipyard can build low cost components cheaper is correct, we need something in the actual ship to reflect a price difference. What we are trying to do here is prevent the cumulative costs getting out of hand. As long it is incremental then Matt's concept of having a bigger budget, can then be applied.